Tetrahydrofuran derivatives from epoxides via group transfer cyclization or reductive radical cyclization of organotellurium and organoselenium intermediates

Article abstract of DOI:10.1021/jo961578n

Monosubstituted epoxides were regiospecifically ring-opened from the sterically least hindered side by benzenetellurolate and benzeneselenolate reagents to afford aryl β-hydroxyalkyl tellurides and selenides, respectively. These materials were O-allylated by treatment with allylic bromides/sodium hydride in tetrahydrofuran and O-prop-2-ynylated when reacted with propargyl bromide/sodium hydride. On photolysis in benzene containing 40 mol % of hexabutylditin, the β-(allyloxy)alkyl aryl tellurides were found to undergo group transfer cyclization to afford 2-substituted 4-[(aryltelluro)methyl]tetrahydrofurans (cis/trans = 1/3-1/10). The aryl β-(prop-2-ynyloxy)alkyl tellurides similarly afforded 2-substituted 4-[(aryltelluro)methylene]tetrahydrofurans with an E/Z-ratio close to unity. The β-(allyloxy)alkyl aryl selenides and aryl β-(prop-2-ynyloxy)alkyl selenides failed to undergo group transfer cyclization. In the presence of tributyltin hydride and 2,2'-azobisisobutyronitrile, the former compounds were found to undergo reductive radical cyclization in high yields to afford 2-substituted 4-methyltetrahydrofurans (cis/trans = 1/3-1/10). Aryl β-(prop-2-ynyloxy)alkyl selenides similarly afforded 2-substituted 4-methylenetetrahydrofurans. 2-Alkoxy-2-(allyloxy)ethyl phenyl selenides, prepared by allyloxyselenenation of vinyl ethers, were found to undergo reductive radical cyclization to afford 2-alkoxy-4-methyltetrahydrofurans (cis/trans = 13-1/4). The preference for formation of trans-2,4-disubstituted tetrahydrofurans in the group transfer and reductive radical cyclizations was rationalized assuming a chairlike transition state with a preferred adoption of a pseudoequatorial position of the 2-substituent. By carrying out the reactions at lower temperatures (ambient or -45°C), using triethylborane as an initiator, it was possible to further increase the trans selectivity in the reductive cyclizations.

Full text of DOI:10.1021/jo961578n

J . Org. Chem. 1997, 62, 157-173
157
Tetr a h yd r ofu r a n Der iva tives fr om Ep oxid es via Gr ou p Tr a n sfer
Cycliza tion or Red u ctive Ra d ica l Cycliza tion of Or ga n otellu r iu m
a n d Or ga n oselen iu m In ter m ed ia tes
Lars Engman* and Vijay Gupta
Institute of Chemistry, Department of Organic Chemistry, Uppsala University, Box 531,
S-751 21 Uppsala, Sweden
Received August 13, 1996X
Monosubstituted epoxides were regiospecifically ring-opened from the sterically least hindered side
by benzenetellurolate and benzeneselenolate reagents to afford aryl â-hydroxyalkyl tellurides and
selenides, respectively. These materials were O-allylated by treatment with allylic bromides/sodium
hydride in tetrahydrofuran and O-prop-2-ynylated when reacted with propargyl bromide/sodium
hydride. On photolysis in benzene containing 40 mol % of hexabutylditin, the â-(allyloxy)alkyl
aryl tellurides were found to undergo group transfer cyclization to afford 2-substituted 4-[(aryl-
telluro)methyl]tetrahydrofurans (cis/trans ) 1/3-1/10). The aryl â-(prop-2-ynyloxy)alkyl tellurides
similarly afforded 2-substituted 4-[(aryltelluro)methylene]tetrahydrofurans with an E/Z-ratio close
to unity. The â-(allyloxy)alkyl aryl selenides and aryl â-(prop-2-ynyloxy)alkyl selenides failed to
undergo group transfer cyclization. In the presence of tributyltin hydride and 2,2′-azobisisobuty-
ronitrile, the former compounds were found to undergo reductive radical cyclization in high yields
to afford 2-substituted 4-methyltetrahydrofurans (cis/trans ) 1/3-1/10). Aryl â-(prop-2-ynyloxy)-
alkyl selenides similarly afforded 2-substituted 4-methylenetetrahydrofurans. 2-Alkoxy-2-(allyloxy)-
ethyl phenyl selenides, prepared by allyloxyselenenation of vinyl ethers, were found to undergo
reductive radical cyclization to afford 2-alkoxy-4-methyltetrahydrofurans (cis/trans ) 1/3-1/4). The
preference for formation of trans-2,4-disubstituted tetrahydrofurans in the group transfer and
reductive radical cyclizations was rationalized assuming a chairlike transition state with a preferred
adoption of a pseudoequatorial position of the 2-substituent. By carrying out the reactions at lower
temperatures (ambient or -45 °C), using triethylborane as an initiator, it was possible to further
increase the trans selectivity in the reductive cyclizations.
In tr od u ction
(k25 ) 5 × 104 s-1).4 There are synthetically useful radical
cyclizations described, though, where the oxygen atom
has been incorporated at positions 1,3,5 2,6,7 3, and 4.8
In addition to transition metal-mediated synthesis, free
radical chemistry has emerged as one of the most
powerful tools in modern synthetic chemistry.1 The rapid
(k25 ) 2 × 105 s-1),2 irreversible, and regioselective (98%
exo) cyclization of the 5-hexenyl radical (eq 1) has not
only been exceedingly useful for the construction of
A vast majority of the tetrahydrofuran syntheses
involve a cyclization of a 3-oxa-5-hexenyl system.9 As
(5) Montaudon, E.; Lubeigt, X.; Maillard, B. J . Chem. Soc., Perkin
Trans. 1 1991, 1531.
(6) Nicolaou, K. C.; McGarry, D. G.; Somers, P. K.; Veale, C. A.;
Furst, G. T. J . Am. Chem. Soc. 1987, 109, 2504. Lolkema, L. D. M.;
Hiemstra, H.; Al Ayashi Al Ghouch; Speckamp, W. N. Tetrahedron
Lett. 1991, 32, 1491. Udding, J . H.; Giesselink, J . P. M.; Hiemstra, H.;
Speckamp, W. N. J . Org. Chem. 1994, 59, 6671.
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1991, 56, 5245. Rawal, V. H.; Singh, S. P.; Dufour, C.; Michoud, C. J .
Org. Chem. 1993, 58, 7718.
(8) Moriya, O.; Urata, Y.; Ikeda, Y.; Ueno, Y.; Endo, T. J . Org. Chem.
1986, 51, 4708.
cyclopentanes but also been applied extensively, via
substitution with oxygen, for the preparation of tetrahy-
drofuran derivatives. As compared to the unperturbed
system, oxygen substitution at positions 1 (k30 ) 4 × 108
s-1)3 and 3 (k25 ) 9 × 106 s-1)4 have an accelerating effect,
whereas substitution at position 2 retards the cyclization
(9) See for example Ladlow, M.; Pattenden, G. Tetrahedron Lett.
1984, 25, 4317. Stork, G.; Kahn, M. J . Am. Chem. Soc. 1985, 107, 500.
Moriya, O.; Kakihana, M.; Urata, Y.; Sugizaki, T.; Kageyama, T.; Ueno,
Y.; Endo, T. J . Chem. Soc., Chem. Commun. 1985, 1401. Stork, G.;
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Brunetiere, A. P.; Lallemand, J . Y. Tetrahedron Lett. 1986, 27, 3715.
Ueno, Y.; Moriya, O.; Chino, K.; Watanabe, M.; Okawara, M. J . Chem.
Soc., Perkin Trans. 1 1986, 1351. Stork, G.; Sher, P. M.; Chen, H.-L.
J . Am. Chem. Soc. 1986, 108, 6384. Morikawa, T.; Nishiwaki, T.; Iitaka,
Y.; Kobayashi, Y. Tetrahedron Lett. 1987, 28, 671. Hutchinson, J . H.;
Pattenden, G.; Myers, P. L. Tetrahedron Lett. 1987, 28, 1313. Begley,
M. J .; Bhandal, H.; Hutchinson, J . H.; Pattenden, G. Tetrahedron Lett.
1987, 28, 1317. Keck, G. E.; Burnett, D. A. J . Org. Chem. 1987, 52,
2958. Audin, C.; Lancelin, J .-M.; Beau, J .-M. Tetrahedron Lett. 1988,
29, 3691. Harrison, T.; Pattenden, G.; Myers, P. L. Tetrahedron Lett.
1988, 29, 3869. De Mesmaeker, A.; Hoffmann, P.; Ernst, B. Tetrahe-
dron Lett. 1989, 30, 57. Chapleur, Y.; Moufid, N. J . Chem. Soc., Chem.
Commun. 1989, 39. Bonini, C. Tetrahedron Lett. 1990, 31, 5369. Maiti,
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T.; Murata, M.; Suzuki, A.; Miyaura, N. J . Chem. Soc., Chem. Commun.
1995, 295. Srikrishna, A.; Viswajanani, R. Sattigeri, J . A. J . Chem.
Soc., Chem. Commun. 1995, 469. Srikrishna, A.; Viswajanani, R.;
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X Abstract published in Advance ACS Abstracts, December 1, 1996.
(1) For recent general reviews and books see: (a) Giese, B. Radicals
in Organic Synthesis: Formation of C-C bonds; Pergamon Press:
Oxford, 1986. (b) Curran, D. P. Synthesis 1988, 417 and 489. (c) Regitz,
M.; Giese, B., Eds. Houben-Weyl, Methoden der Organischen Chemie;
band E19a, C-Radikale, Teil 1+2, Georg Tieme Verlag: Stuttgart,
1989. (d) Curran, D. P. In Comprehensive Organic Synthesis; Trost,
B. M., Fleming, I., Semmelhack, M. F., Eds.; Pergamon Press: Oxford,
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Radical Chain Reactions in Organic Synthesis; Academic Press: New
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Chemistry; Wiley: New York, 1995.
(2) Chatgilialoglu, C.; Ingold, K. U.; Scaiano, J . C. J . Am. Chem.
Soc. 1981, 103, 7739.
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Lett. 1995, 36, 3643.
S0022-3263(96)01578-2 CCC: $14.00 © 1997 American Chemical Society

158 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
Sch em e 1
stituted epoxides, highly regiospecific (secondary and
tertiary alcohols, respectively, formed). With unsym-
metrical 1,2-disubstituted epoxides, mixtures of regioi-
somers are usually obtained. In the present investiga-
tion, monosubstituted (R′ ) H) and symmetrical
disubstituted epoxides (R ) R′) were treated with ben-
zenetellurolate and benzeneselenolate ions in ethanol at
ambient temperature to afford â-hydroxyalkyl aryl tel-
lurides and selenides as shown in eq 2. The required
organochalcogen reagents were conveniently prepared
from sodium borohydride and the respective diaryl
dichalcogenides in ethanol under nitrogen. The yields
and structures of the aryl â-hydroxyalkyl tellurides and
aryl â-hydroxyalkyl selenides prepared are reported in
Tables 1 and 2, respectively. In contrast to the other
monosubstituted epoxides (1,2-epoxy-5-hexene, 1,2-ep-
oxybutane, 3-(allyloxy)-1,2-epoxypropane, 1,2-epoxy-3-
phenoxypropane and 3-(benzyloxy)-1,2-epoxypropane),
styrene oxide afforded a 56/44-mixture of the two possible
ring-opening products 1m and 2a (94% yield). A simi-
larly low regioselectivity has previously been observed
in the benzeneselenolate induced ring-opening of styrene
oxide.19,20 However, both isomers were useful in the
following allylation/propargylation and radical chemistry.
By treatment of styrene oxide with sodium 4-(trifluorom-
ethyl)benzenetellurolate, the secondary alcohol 1f (Table
1) was the only isomer that could be isolated in a pure
form (50% yield). As a representative of a 2,2-disubsti-
tuted terminal epoxide, 1,2-epoxy-2-methylpropane, was
ring-opened from the sterically least hindered side by
tellurolate and selenolate reagents. However, all at-
tempts to allylate the resulting tertiary alcohols met with
failure.
originally described by the groups of Ueno10 and Stork,11
the precursors to such radicals can be conveniently
assembled from allylic alcohols, vinyl ethers/olefins, and
a source of positive halogen (Scheme 1, upper part).
Except for this methodology, few general methods are
known for radical precursor synthesis. The scarce ex-
amples reported include the conjugate addition12,13 and
allylation14 of allylic alcohols as well as some other
methods.15,16
We thought it was possible to prepare tetrahydrofuran
derivatives from epoxides by a series of operations
involving ring-opening with a nucleophilic reagent X,
O-allylation, and reductive radical cyclization (Scheme
1, lower part). It is required, though, that the nucleo-
philic reagent has the additional capacity to act as a
source of a carbon-centered radical. We recently reported
the ring-opening of epoxides by arenetellurolate ion and
the preparation of tetrahydrofuran derivatives by a
hexabutylditin/light-induced group transfer cyclization
reaction of the O-allylated telluride (Scheme 1, lower
part).17 In the following, we report a full account of this
and related work with the corresponding organoselenium
compounds.
Resu lts
Allyla tion a n d P r op a r gyla tion of Ar yl â-Hyd r oxy-
a lk yl Tellu r id es a n d Selen id es. By treatment with
allyl bromide in tetrahydrofuran in the presence of
sodium hydride, the aryl â-hydroxyalkyl tellurides and
selenides 1 were O-allylated without competing epoxide
formation (eq 3, Tables 1 and 2). Some of the compounds
(1m , 1o, 1p ; Table 2) were similarly O-prenylated using
4-bromo-2-methyl-2-butene and most of them were O-prop-
2-ynylated by treatment with propargyl bromide (eq 3,
Tables 1 and 2). Selenide 2a was allylated, prenylated,
and prop-2-ynylated, respectively, to give compounds 2b,
2c, and 2d .
Rin g-Op en in g of Ep oxid es by Tellu r ola te a n d
Selen ola te Rea gen ts. Epoxides are readily ring-opened
by tellurolate and selenolate reagents.18 The reaction is
anti stereospecific, and, in the case of mono and trisub-
(10) Ueno, Y.; Chino, K.; Watanabe, M.; Moriya, O.; Okawara, M.
J . Am. Chem. Soc. 1982, 104, 5564.
(11) Stork, G.; Mook, R., J r.; Biller, S. A.; Rychnovsky, S. D. J . Am.
Chem. Soc. 1983, 105, 3741.
(12) Ono, N.; Miyake, H.; Kamimura, A.; Hamamoto, I.; Tamura,
R.; Kaji, A. Tetrahedron 1985, 41, 4013.
(13) Ueno, Y.; Khare, R. K.; Okawara, M. J . Chem. Soc., Perkin
Trans. 1 1993, 2637.
(14) Smith, T. A. K.; Whitham, G. H. J . Chem. Soc., Chem. Commun.
1985, 897. Bertrand, M. P.; De Riggi, I.; Lesueur, C.; Gastaldi, S.;
Nouguier, R.; J aime, C.; Virgili, A. J . Org. Chem. 1995, 60, 6040.
(15) Watanabe, Y.; Endo, T. Tetrahedron Lett. 1988, 29, 321.
(16) Okabe, M.; Tada, M. Bull. Chem. Soc. J pn. 1982, 55, 1498.
(17) Engman, L.; Gupta, V. J . Chem. Soc., Chem. Commun. 1995,
2515.
(18) Back, T. G. In The Chemistry of Organic Selenium and
Tellurium Compounds; Patai, S., Ed.; Wiley: New York, 1987; Vol. 2,
p 171.
(19) Sakakibara, M.; Katsumata, K.; Watanabe, Y.; Toru, T.; Ueno,
Y. Synthesis 1992, 377.
(20) Engman, L.; Stern, D. J . Org. Chem. 1994, 59, 5179. For
methods to control the regioselectivity in the benzeneselenolate-induced
ring-opening of styrene oxide see: Miyoshi, N.; Kondo, K.; Murai, S.;
Sonoda, N. Chem. Lett. 1979, 909. Cravador, A.; Krief, A. Tetrahedron
Lett. 1981, 22, 2491. Ley, S. V.; O’Neil, I. A.; Low, C. M. R. Tetrahedron
1986, 42, 5363.

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 159
Ta ble 1. Or ga n otellu r iu m Gr ou p Tr a n sfer Cycliza tion P r od u cts a n d In ter m ed ia tes

160 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
Ta ble 1. (Con tin u ed )
ticularly true for the organotellurium compounds. As
indicated in Table 1, attempted chromatographic puri-
fication seemed to reduce the isolated yields of the prop-
2-ynylated tellurides. Therefore, the following free radi-
cal chemistry (vide infra) was better performed by using
the crude reaction product.
Gr ou p Tr a n sfer Cycliza tion Rea ction s. In atom
and group transfer-mediated radical reactions an atom
A (hydrogen,24 halogen,25 or metal26) or a group G (such
as SePh27) is transferred in the chain-transfer step from
a neutral molecule to a radical to form a new σ-bond and
a new radical (Scheme 2). For such processes to be
synthetically useful, the atom/group transfer step has to
be preceded by a radical addition, cyclization, annulation,
or fragmentation reaction. Due to work of the Barton
The prop-2-ynylated derivatives were prepared as
precursors to 3-oxa-5-hexynyl radicals. These are known
to readily cyclize in a 5-exo mode to afford 3-methylene-
tetrahydrofurans.21-23 So far, precursors to such radicals
were available from propargylic alcohols and olefins by
using the chemistry shown in the upper part of Scheme
1.
(24) Curran, D. P.; Min Shu. Bull. Soc. Chim. Fr. 1993, 130, 314
and refs cited therein.
(25) Curran, D. P.; Kim, D. Tetrahedron Lett. 1986, 27, 5821.
Curran, D. P.; Chang, C.-T. Tetrahedron Lett. 1987, 28, 2477. Curran,
D. P.; Chen, M.-H. J . Am. Chem. Soc. 1987, 109, 6558. Curran, D. P.;
Seong, C. M. J . Am. Chem. Soc. 1990, 112, 9401.
In general, O-prop-2-ynylation was effected in poorer
yield than the correponding allylation. This was par-
(26) Gill, G. B.; Pattenden, G.; Reynolds, S. J . J . Chem. Soc., Perkin
Trans. 1 1994, 369 and refs cited therein.
(21) Okabe, M.; Abe, M.; Tada, M. J . Org. Chem. 1982, 47, 1775.
(22) Tanaka, H.; Suga, H.; Ogawa, H.; Abdul Hai, A. K. M.; Torii,
S.; J utand, A.; Amatore, C. Tetrahedron Lett. 1992, 33, 6495.
(23) Okabe, M.; Tada, M. J . Org. Chem. 1982, 47, 5382. Stork, G.;
Mook, R., J r. J . Am. Chem. Soc. 1983, 105, 3720. Srikrishna, A.;
Pullaiah, K. C. Tetrahedron Lett. 1987, 28, 5203. Srikrishna, A.;
Sunderbabu, G. Tetrahedron Lett. 1987, 28, 6393. Ariamala, G.;
Balasubramanian, K. K. Tetrahedron Lett. 1988, 29, 3335. Dulce`re,
J .-P.; Baret, N.; Rodriguez, J .; Faure, R. Synlett 1995, 705. Dulce`re,
J .-P.; Dumez, E.; Faure, R. J . Chem. Soc., Chem. Commun. 1995, 897.
Cossy, J .; Ranaivosata, J .-L.; Bellosta, V. Tetrahedron Lett. 1995, 36,
2067. Tada, M.; Kaneko, K. J . Org. Chem. 1995, 60, 6635.
(27) Byers, J . H.; Lane, G. C. Tetrahedron Lett. 1990, 31, 5697.
Byers; J . H.; Gleason, T. G.; Knight, K. S. J . Chem. Soc., Chem.
Commun. 1991, 354. Byers, J . H.; Harper, B. C. Tetrahedron Lett. 1992,
33, 6953. Pandey, G.; Sesha Poleswara Rao, K. S.; Soma Sekhar, B. B.
V. J . Chem. Soc., Chem. Commun. 1993, 1636. Byers, J . H.; Lane, G.
C. J . Org. Chem. 1993, 58, 3355. Curran, D. P.; Eichenberger, E.; Collis,
M.; Roepel, M. G.; Thoma, G. J . Am. Chem. Soc. 1994, 116, 4279.
Curran, D. P.; Geib, S. J .; Kuo, L. H. Tetrahedron Lett. 1994, 35, 6235.
Renaud, P.; Abazi, S. Synthesis 1996, 253. Byers, J . H.; Whitehead,
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Gladstone, P. L.; Parvez, M. J . Org. Chem. 1996, 61, 3806.

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 161
Ta ble 2. Red u ctive Ra d ica l Cycliza tion P r od u cts a n d Or ga n oselen iu m In ter m ed ia tes
group, diorganyl tellurides are known to act as efficient
exchangers of carbon-centered radicals.28 Furthermore,
rate data from Currans group29 indicate that TePh group
transfer occurs as readily as iodine atom transfer. It is
therefore surprising to find so few examples where the
synthetic potential of group transfer chemistry has been

162 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
Sch em e 2
taken advantage of. The scarce examples reported so far
include the photostimulated cyclization of unsaturated
acyl tellurides30 and the AIBN-induced group transfer
addition of diorganyl tellurides to acetylenes.31
During the initial explorative phase of the present
project, 2-hydroxy-5-hexenyl phenyl telluride 1a was
heated at reflux in benzene together with AIBN and
allyltributyltin. In addition to small amounts of the
expected radical cyclization/allylation product, we iso-
lated the radical cyclization/group transfer product 5a
as the major product (eq 4). Our efforts to optimize the
the strongly accelerating effect of a 3-oxa substituent in
5-hexenyl and 5-hexynyl radical cyclization.32 Group
transfer products of type 6 (60-70% yields) and 7 (40-
50% yields) with a substantial variation in the 2-sub-
stituent were prepared as shown in Table 1 [R′ ) H, R )
ethyl, phenyl, (allyloxy)methyl, phenoxymethyl, or (ben-
zyloxy)methyl; R, R′ ) (CH2)4]. The tetrahydrofuran
derivatives 6 were obtained as mixtures of cis and trans
isomers. The isomeric composition and the assignment
of 1H NMR spectra to the isomers were based on NOESY,
NOE-difference and ZTOCSY experiments (vide infra).
As shown in Table 1, the trans isomer always predomi-
nated with a ratio of 3/1-10/1 over the cis isomer.
Bicyclic compounds 6j and 6k were isolated as 2/1
mixtures of exo and endo isomers, both with a cis ring
fusion.
The tetrahydrofuran derivatives 7 were isolated as
(sometimes separable) mixtures of E and Z isomers. The
isomeric composition and the assignment of 1H NMR
spectra to the isomers were based on NOESY, NOE-
difference, and ZTOCSY experiments. As shown in Table
1, the E/Z ratio was always close to unity. The product
yields for group transfer cyclization to an acetylene were
always inferior to those obtained with the corresponding
olefinic compounds. Due to problems in the purification
of the O-prop-2-ynylated aryl â-hydroxyalkyl tellurides,
group transfer cyclization was somtimes attempted using
the crude prop-2-ynylation product (Table 1). Product
yields never exceeded 50%. Due to inversion at the
radical center, the bicyclic tetrahydrofuran 7j was ob-
tained as an E/Z-mixture of cis fused compounds.
With the perspective to increase the diastereoselectiv-
ity in the group transfer cyclization reactions, other
initiators were sought which could be effective at lower
temperatures than those used in the above photochemical
process. Triethylborane in the presence or absence of air
has been used, at or below room temperature, to induce
group transfer cyclization,33 reductive radical cycliza-
tion7,34 as well as other free radical chemistry such as
addition35 and substitution36 reactions. When telluride
3j was treated in toluene at ambient temperature with
1.2 equiv. of triethylborane under an atmosphere of
nitrogen, the group transfer product 6j was isolated in
60% yield after 5 h. However, the diastereoselectivity
(exo/endo ) 2/1) did not differ from that observed at 80
°C. Although the mild reaction conditions and the
absence of organotin compounds are attractive features
of this reaction, we generally found it less useful than
conditions for cyclization/group transfer showed that the
desired product was formed in good yield by sun lamp
irradiation of a 0.05-0.1 M refluxing solution of the
telluride in benzene under nitrogen in the presence of
40 mol % of hexabutylditin. Among the different aryl
groups tested (Table 1, compounds 1a -d ), the 4-(trifluo-
romethyl)phenyl group turned out to be superior with
respect to the time required to obtain complete conversion
of the starting material (2 h for compound 1c as com-
pared to 4-6 h for the other three compounds). Also, as
compared with the other derivatives, the compounds
carrying a 4-(trifluoromethyl)phenyl group showed an
increased stability during storage, handling, and chro-
matographic purification. The cyclopentane derivatives
5a -d were all obtained as mixtures containing near to
equal amounts of the cis and trans compounds. The
isomeric composition of product 5a was determined after
benzoylation, hydrodetelluration (Bu3SnH/AIBN/reflux-
ing benzene) and comparison with an authentic sample
obtained by benzoylation of commercially available 3-me-
thylcyclopentanol. The isomeric composition of products
1
5b-d was assigned directly from their H NMR spectra
in analogy with the result for compound 5a .
When irradiated in the presence of hexabutylditin,
O-allylated and O-prop-2-ynylated aryl â-hydroxyalkyl
tellurides 3 and 4 were found to cyclize with group
transfer to form tetrahydrofuran derivatives 6 and 7,
respectively (eq 5, Table 1). Also in the cases where the
R group contained unsaturation (R ) 3-butenyl, R′ ) H;
Table 1, compounds 3d and 4c) products of carbocycliza-
tion were not detected. This is not surprising in view of
(28) Barton, D. H. R.; Ozbalik, N.; Sarma, J . C. Tetrahedron Lett.
1988, 29, 6581.
(29) Curran, D. P.; Martin-Esker, A. A; Ko, S.-B.; Newcomb, M. J .
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(32) See ref 1f, p 151.
(33) Ichinose, Y.; Matsunaga, S.; Fugami, K.; Oshima, K.; Utimoto,
K. Tetrahedron Lett. 1989, 30, 3155.
(34) Clive, D. L. J .; Manning, H. W.; Boivin, T. L. B.; Postema, M.
H. D. J . Org. Chem. 1993, 58, 6857.
(35) Ichinose, Y.; Wakamatsu, K.; Nozaki, K.; Birbaum, J .-L.;
Oshima, K., Utimoto, K. Chem. Lett. 1987, 1647. Nozaki, K.; Oshima,
K.; Utimoto, K. J . Am. Chem. Soc. 1987, 109, 2547. Benati, L.; Capella,
L.; Montevecchi, P. C.; Spagnolo, P. J . Org. Chem. 1995, 60, 7941.
(36) Baciocchi, E.; Muraglia, E. Tetrahedron Lett. 1993, 34, 5015.

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 163
the photochemical method for the initiation of group
transfer cyclization in primary tellurides.
prepared in 40-70% yields from acetylenic compounds
3 under the standard radical cyclization conditions (eq
6, Table 2). 4-Methylene-3-phenyltetrahydrofuran (13)
was isolated in 70% yield under the similar conditions.
Some reductive cyclizations were also tried at lower
temperatures under nitrogen, using triethylborane as the
initiator. Thus, in the presence of tributyltin hydride,
the cis/trans ratio of compound 11 was lowered from 1/3
at 80 °C to 1/3.3 at 25 °C and 1/6 at -45 °C. The isolated
yields at the respective temperatures were 85, 73, and
52%.
Red u ctive Ra d ica l Cycliza tion . Although the phen-
ylseleno group is known to undergo group transfer
reactions,27 all attempts to effect group transfer cycliza-
tion with O-allylated or O-prop-2-ynylated â-hydroxyalkyl
phenyl selenides 3 and 4 met with failure. On the other
hand, these materials were found to undergo reductive
radical cyclization on treatment with AIBN and tribu-
tyltin hydride under standard conditions avoiding the use
of a syringe pump (eq 6). Similar reactions are not
without precedence in the literature. However, the
Already in 1978, Petrzilka39 reported the regiospecific
addition of phenylselenenyl bromide to ethyl vinyl ether
and the base-induced substitution of the bromine with
various allylic alcohols (eq 7). The products 14 would
be expected (cf. Scheme 1, upper part) to serve as
required organoselenium radical precursors were usually
prepared by less general37 or less direct38 methods.
2-Hydroxy-5-pentenyl phenyl selenide (1l, Table 2)
afforded the carbocycle 3-methylcyclopentanol (8) in 52%
yield as a 1.3/1 mixture of cis and trans isomers. As was
the case in the telluride series, its O-allylated derivative
(3l) afforded only the product resulting from 3-oxa-5-
hexenyl radical cyclization. In Table 2, the preparation
of a variety of substituted 4-methyltetrahydrofurans 9
[R′ ) H, R ) 3-butenyl, phenyl, (allyloxy)methyl, phe-
noxymethyl, or (benzyloxy)methyl; R ) R′ ) (CH2)4] and
4-isopropyltetrahydrofurans 9 (R′ ) H, R ) phenyl,
phenoxymethyl, or (benzyloxy)methyl) in 80-90% yields
from selenides 3 are reported. The isomeric composition
and the assignment of the lH NMR spectra to the isomers
were performed as described above for group transfer
products and exemplified below. The trans isomers of
the 2-substituted 4-methyltetrahydrofurans predomi-
nated, usually with a ratio of 3/1-4/1 over the cis isomers.
However, a significantly lower selectivity (trans/cis ) 1.3/
1-2/1) was observed for the 2-substituted 4-isopropyltet-
rahydrofurans prepared (compounds 9m ′, 9o′, and 9p ′;
Table 2). The two 3,4-disubstituted tetrahydrofurans
synthesized (compounds 11 and 12) were obtained pre-
dominantly (3/1 and 2/1, respectively) as trans isomers.
The bicyclic compound 9q was isolated as a 1.5 /1 mixture
of cis fused exo and endo isomers.
excellent precursors to 2-alkoxy-4-methyltetrahydro-
furans via 3-oxa-5-hexenyl radical cyclization. Some
compounds of this type were therefore prepared and the
diastereoselectivity of the cyclization determined. When
submitted to the standard reaction conditions, com-
pounds 14a -c afforded the 2-alkoxy-4-methyltetrahy-
drofurans 15a -c in 66, 76, and 76% yields, respectively.
The trans isomers predominated with a ratio of 4/1 for
the two former compounds and with a ratio of 3/1 for the
latter. In the preparation of compound 14c, it was found
essential to use phenylselenenyl chloride to obtain the
desired product in fair yield (65%). When 3,4-dihydro-
pyran was treated with phenylselenenyl bromide and
then with allyl alcohol/triethylamine, the elimination
product 16 was the only material isolated (68% yield).
However, by using phenylselenenyl chloride instead of
the bromide, the desired alkoxyselenenation product 17
was obtained in 54% yield. Reductive cyclization of this
material afforded the bicyclic tetrahydrofuran derivative
18 as a 1/4 mixture of cis fused exo and endo isomers
(69% yield). As noted above, triethylborane-induced
reductive cyclizations at ambient temperature under
nitrogen occurred with improved diastereoselectivities.
Thus, compounds 15a and 15b were obtained as 1/6
mixtures of cis and trans isomers at 25 °C. Similarly,
the exo/endo ratio of compound 18 dropped to 1/16 at
ambient temperature. However, since the ratio at 80 °C
in the triethylborane-initiated reaction was 1/8, this
dramatic difference may only in part be ascribed to the
effect of the temperature.
2-Substituted 4-methylenetetrahydrofurans 10 [R′ )
H, R ) 3-butenyl, phenyl, (allyloxy)methyl, phenoxym-
ethyl, or (benzyloxy)methyl; R ) R′ ) (CH2)4] were
(37) De Mesmaeker, A.; Hoffmann, P.; Ernst, B.; Hug, P.; Winkler,
T. Tetrahedron Lett. 1989, 30, 6307. De Mesmaeker, A.; Hoffmann,
P.; Ernst, B.; Hug, P.; Winkler, T. Tetrahedron Lett. 1989, 30, 6311.
De Mesmaeker, A.; Waldner, A.; Hoffmann, P.; Hug, P.; Winkler, T.
Synlett. 1992, 285.
Deter m in a tion of Dia ster eoselectivity. The as-
signment of cis/trans, E/Z, and exo/endo isomers of the
(38) Clive, D. L. J .; J oussef, A. C. J . Chem. Soc., Perkin Trans 1
1991, 2797.
(39) Petrzilka, M. Helv. Chim. Acta 1978, 61, 2286.

164 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
assuming a chairlike transition state with a preferred
adoption of a pseudoequatorial position of the substitu-
ent.40 In accord with this model, 2-methyl- and 4-methyl-
5-hexenyl radicals were found to cyclize with preferential
formation of the trans disubstituted cyclopentane whereas
the 3-methyl derivative afforded mainly cis-1,3-dimeth-
ylcyclopentane. On cyclization, the 1-methyl-5-hexenyl
radical afforded mainly the cis isomer. However, calcula-
tion and experiment suggest that the diastereoselectivity
could be inverted by introduction of a bulky 1-substitu-
ent.41 In contrast to the product obtained from reductive
cyclization of the 2-methyl-5-hexenyl radical, the group
transfer (compounds 5a -d ) and reductive cyclization
products (compound 8) derived from the 2-hydroxy-5-
hexenyl radical were isolated mainly as cis-1,3 disubsti-
tuted cyclopentanes. The reason for this change in
diastereoselectivity in not obvious. One may speculate
that the pseudoaxially oriented hydroxyl group avoids an
unfavorable interaction with the singly occupied molec-
ular orbital (SOMO) in the transition state 19.
F igu r e 1.
various tetrahydrofuran derivatives prepared were based
on NOESY and/or NOE difference experiments. As
representative examples, the NOE enhancements ob-
served for the trans isomer of compound 6h and the endo
isomer of compound 18 are shown in Figure 1. Usually,
it was possible to establish the relative 1,3-stereochem-
istry by either, or both, of two routes. As shown for
compound 6h , the 1,3-trans stereochemistry is suggested
by the cis arrangement of Ha/Hf and Hd/He and also by
the cis arrangement of Ha/Hb and Hc/Hd. Due to overlap-
ping signals of Hb and Hc, the latter route sometimes
failed. Exo and endo isomers were similarly distin-
guished as shown for endo-18 (Figure 1).
All group transfer and reductive cyclization reactions
involving 2-substituted 3-oxa-5-hexenyl radicals afforded
the trans-2,4-disubstituted tetrahydrofuran as the pre-
dominating diastereomer. However, for most of the
reactions the selectivity was only moderate (2/1-4/1) and
usually very similar for group transfer cyclization (Table
1) and reductive cyclization (Table 2) products derived
from the same epoxide. These results can be rationalized
by invoking a chairlike transition state 20 for the ring-
closures, with the substituent occupying a pseudoequa-
torial position. Some group transfer and reductive
radical cyclizations occurred with significantly higher
diastereoselectivities than the others (6g; cis/trans )
1/10, 6i; cis/trans ) 1/10;42 9n ; cis/trans ) 1/10). The
similar results with compounds 6g and 9n may indicate
that the increased selectivity is caused by the tetrahy-
drofuran 2-substituent. However, the reductive cycliza-
tion of compound 3p afforded tetrahydrofuran 9p with a
significantly poorer (cis/trans ) 1/3) selectivity than was
obtained in the corresponding group transfer cyclization.
Therefore, telluride 3i was subjected to reductive radical
cyclization. By using the standard procedure for se-
lenides, compound 9p was isolated in 86% yield as a 1/3
mixture of cis and trans isomers. One remaining hy-
pothesis to explain the high diastereoselectivity in the
formation of compound 6i involves participation of the
hexabutylditin in the transition state of the group
transfer reaction.
Discu ssion
In the present paper, we have demonstrated a novel
versatile route to 3-oxa-5-hexenyl and 3-oxa-5-hexynyl
radical precursors based on ring-opening of epoxides with
arenetellurolate or areneselenolate reagents and O-ally-
lation/O-prop-2-ynylation. Due to the facile group trans-
fer of the aryltelluro group, the organotellurium com-
pounds were transformed by light/hexabutylditin into
2-substituted tetrahydrofuran derivatives 6 and 7, car-
rying an aryltelluro group in the 4-methyl and 4-meth-
ylene substituents, respectively. These products are
probably formed as outlined in Scheme 2 (G ) TeAr; In
) Bu3Sn; [3-oxa-5-hexenyl or 3-oxa-5-hexynyl cycliza-
tion]). Photostimulated atom transfer reactions with
iodine have previously been effected by using only 10 mol
% of hexabutylditin.25 However, to obtain high conver-
sions of the organotellurium starting materials within
reasonable time (2-3 h), as much as 40 mol % of
hexabutylditin was required. Since the cyclization and
group transfer steps in Scheme 2 could be expected to
be fast, this may be due to a relatively inefficient
initiation process.
Group transfer of the phenylseleno group has been
demonstrated both in addition and cyclization reactions.
However, under the conditions where aryltelluro group
transfer was successful (hexabutylditin/light, triethylbo-
rane), the corresponding organoselenium compounds
failed to react. This difference may be a consequence of
poor initiation and a low rate of phenylseleno group
transfer.29 In the presence of an efficient hydrogen atom
donor (tributyltin hydride) and an initiator (AIBN or
triethylborane) products of reductive radical cyclization
were rapidly formed, uncontaminated by any uncyclized
reduction products even under conditions of high tin
hydride concentration.
With respect to diastereoselectivity, the methodology
presented herein for the preparation of 2,4-disubstituted
tetrahydrofurans is complementary to the procedure
described by Rawal (eq 8).7 The cis-selectivity in this
reaction is again explainable by assuming a chairlike
transition state with an equatorial substituent in the
(40) Beckwith, A. L. J .; Schiesser, C. H. Tetrahedron 1985, 41, 3925
and references cited therein.
(41) See ref 1e, p 214, and references cited there.
(42) The cis/trans ratio of this compound was erroneously reported
as <1/20 in our preliminary communication of part of this work (see
reference 17).
The diastereoselectivity observed in the cyclization of
substituted 5-hexenyl radicals has been rationalized

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 165
rahydrofuran derivatives. In most cases, the diastereo-
selectivity in the radical cyclization to an alkene was only
moderate, in favor of the functionalized (compounds 6)
or unfunctionalized (compounds 9) trans-2,4-disubstitut-
ed tetrahydrofuran. However, in some noteworthy cases
(cf. compounds 6g, 6i, 9n , 18) a significantly higher
selectivity was obtained. Although the reasons for the
improved selectivity are not yet fully understood, it may
be possible to improve it further by the proper choice of
substituents and reaction conditions.
Since a handle for further manipulation is retained in
the molecule, the group transfer products 6 and 7 are
synthetically more valuable than their reductive radical
cyclization counterparts 9 and 10. For instance, the
organotellurium compounds are likely to undergo lithium-
tellurium exchange on treatment with alkyllithium re-
agents.43 Also, vinylic tellurides have recently been
shown to be convertible into vinylic cyanocuprates,44,45
or, depending on the conditions, to undergo cross-coupling
reactions with cyanocuprates.45,46 4-Methylenetetrahy-
drofurans 10 are readily oxidzed in the 5-position21,47 and
would therefore be useful for the preparation of R-me-
thylene-γ-lactones. Last but not least, it is important to
emphasize that the synthetic sequence leading to tet-
rahydrofuran derivatives 6, 7, 9, and 10 is also well
suited for asymmetric synthesis. The required, enantio-
merically pure, epoxides are nowadays readily available
by Sharpless epoxidation. Work in this direction is
already ongoing in our laboratories.
3-position. It must be emphasized, though, that the
radical precursors of this synthesis generally are less
available than the ones described in the present work.
The cis and trans isomers of 4-methyl-2-phenyltetrahy-
drofuran were previously prepared with good stereocon-
trol by reductive radical cyclization of allyl 1-phenyl-2,2,2-
trichloroethyl ether and allyl 2,2-dichloro-1-phenyl ether,
respectively, followed by reductive removal of remaining
chlorine atoms.15
In view of the bulky 3-substituent,41 the preferential
formation of trans 3,4-disubstituted tetrahydrofurans 11
and 12 is not difficult to understand. It is more difficult
to rationalize the higher selectivity for the methyl than
for the isopropyl compound. Similarly, it is noteworthy
that the diastereoselectivity in the reductive cyclization
is significantly lower for O-prenylated (compounds 2c,
3m ′, 3o′, and 3p ′) than for O-allylated (compounds 2b,
3m , 3o, and 3p ) phenyl â-hydroxyalkyl selenides.
Due to inversion of configuration at the radical center
prior to cyclization, the bicyclic tetrahydrofuran deriva-
tives 6j, 6k , 7j, 9q, 10q, and 18 are all cis fused.
Compounds 6j, 6k , and 9q were isolated predominantly
as exo isomers. This stereochemistry would result if
cyclization occurs via a chairlike transition state 21 with
a pseudoaxial substituent at position 1 and a pseu-
doequatorial substituent at position 2 of the 3-oxa-5-
hexenyl radical. The high preference for formation of the
endo isomer of compound 18 may be ascribed to the
anomeric effect. In the chairlike transition state 22, the
Exp er im en ta l Section
All epoxides used were commercially available except for
3-(benzyloxy)-1, 2-epoxypropane which was prepared according
to a published procedure.48 Bis[4-(trifluoromethyl)phenyl]-
ditelluride,49 diphenyl ditelluride,49 bis[4-(dimethylamino)-
phenyl]ditelluride,49 and bis(2-thienyl)ditelluride50 were pre-
pared according to literature methods. Benzene was freshly
distilled from calcium hydride. Unless otherwise stated, all
1D and 2D NMR spectra were recorded in CDCl3 on a 400 MHz
NMR spectrometer operating at 399.951 MHz (1H NMR) and
100.578 MHz (13C NMR). J values are given in Hz using the
following abbreviations: s (singlet), br s (broad singlet), t
(triplet), m (multiplet), q (quartet), quint (quintet). EI mass
spectra were recorded at 70 eV. M+-ions were given for 130Te
and 80Se. Elemental analyses were performed by Analytical
Laboratories, Lindlar, Germany, and the Research Institute
for Pharmacy and Biochemistry, Prague, Czech Republic.
Typ ica l P r oced u r e for th e P r ep a r a tion of Ar yl 2-Hy-
d r oxya lk yl Tellu r id es a n d Selen id es. P r ep a r a tion of
3-(Ben zyloxy)-2-h yd r oxyp r op yl P h en yl Selen id e (1p ).
Sodium borohydride (0.49 g, 13 mmol) was added, in portions,
to a stirred suspension of diphenyl diselenide (2.03 g, 6.5 mmol)
in absolute ethanol (50 mL) till a clear colorless and homog-
enous solution was obtained. 3-(Benzyloxy)-1,2-epoxypropane
(2.13 g, 13 mmol) was then added, and the resultant light
yellow solution was stirred for 1 h. Water (50 mL) was added,
and the mixture was extracted with diethyl ether (3 × 30 mL),
the combined organic phases were washed with water and
later with saturated sodium chloride and dried (Na2SO4), and
oxygen 2-substituent of the 3-oxa-5-hexenyl radical is
occupying a pseudoaxial position. This arrangement
would allow for interaction between the lone pair elec-
trons of the 3-oxa substituent and the σ* orbital associ-
ated with the bond to the 2-substituent. As compared
to the AIBN-initiated reaction (exo/endo ) 1/4), the
observed increased diastereoselectivity at 80 °C in the
triethylborane-initiated reaction (exo/endo ) 1/8) may
result from an amplified anomeric effect due to coordina-
tion of the electron deficient boron to the pseudoaxial
oxygen.
Con clu sion s a n d Ou tlook
(43) For the preparation of organolithium compounds via lithium-
tellurium exchange, see Engman, L.; Stern, D. Organometallics 1993,
12, 1445, references 12 through 18.
(44) Marino, J . P.; Tucci, F.; Comasseto, J . V. Synlett 1993, 761.
(45) Chieffi, A.; Comasseto, J . V. Tetrahedron Lett. 1994, 35, 4063.
(46) Chieffi, A.; Comasseto, J . V. Synlett 1995, 671.
(47) Dauben, W. G.; Lorber, M.; Fullerton, D. S. J . Org. Chem. 1969,
34, 3587. Ratcliffe, R.; Rodehorst, R. J . Org. Chem. 1970, 35, 4000.
(48) Mouzin, G.; Cousse, H.; Rieu, J .-P.; Duflos, A. Synthesis 1983,
117.
(49) Engman, L.; Persson, J . J . Organomet. Chem. 1990, 388, 71.
(50) Engman, L.; Cava, M. P. Organometallics 1982, 1, 470.
In the present paper, we have demonstrated the use
of radical-based methodology for the construction of a
variety of substituted, functionalized (tellurides), or
unfunctionalized tetrahydrofuran derivatives from readily
available epoxides. Although simple looking, the tellu-
rolate/selenolate ring-opening-, O-allylation/propargyla-
tion-, and group transfer cyclization/reductive radical
cyclization sequence has, to the best of our knowledge,
not been previously applied for the preparation of tet-

166 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
the solvent was removed in vacuo. The residue was purified
by flash chromatography (40% ether/pentane) to give 3.76 g
(90%) of the title compound. 1H NMR δ 2.68 (d, J ) 4.7 Hz,
1H), 3.03 (dd, J ) 12.7, 6.9 Hz, 1H), 3.09 (dd, J ) 12.7, 5.7
Hz, 1H), 3.51 (dd, J ) 9.5, 5.9 Hz, 1H), 3.56 (dd, 9.5, 4.1 Hz,
1H), 3.93 (m, 1H), 4.49 (s, 2H), 7.22-7.37 (several peaks, 8H),
7.50 (m, 2H). 13C NMR δ 31.91, 69.43, 72.83, 73.36, 127.13,
127.70, 127.76, 128.40, 129.13, 129.56, 132.77, 137.76. Anal.
Calcd for C16H18O2Se: C, 59.82; H, 5.65. Found: C, 59.52; H,
5.64. MS m/ z (relative intensity) 322 (M+, 4.9).
3-(Ben zyloxy)-2-h yd r oxyp r op yl 4-(t r iflu or om et h yl)-
p h en yl tellu r id e (1i): H NMR δ 2.73 (d, J ) 4.1 Hz, 1H),
1
3.10 (dd, J ) 12.1, 5.8 Hz, 1H), 3.15 (dd, J ) 12.0, 6.5 Hz,
1H), 3.49 (dd, J ) 9.5, 6.2 Hz, 1H), 3.56 (dd, J ) 9.5, 3.9 Hz,
1H), 4.02 (m, 1H), 4.50 (s, 2H), 7.27-7.42 (several peaks, 7H),
7.78 (m, 2H). 13C NMR δ 14.1, 70.2, 73.4, 73.9, 117.7, 125.4,
125.6 (q), 127.7, 127.9, 128.5, 129.6 (q), 137.5, 137.5. MS m/ z
(relative intensity) 440 (M+, 2.3).
2-Hyd r oxycycloh exyl 4-(tr iflu or om eth yl)p h en yl tel-
lu r id e (1j): 1H NMR δ 1.17-1.38 (several peaks, 3H), 1.50-
1.65 (several peaks, 2H), 1.80 (m, 1H), 2.16 (m, 1H), 2.30 (m,
1H), 2.49 (d, J ) 3.1 Hz, 1H), 3.19 (ddd, J ) 12.3, 10.2, 3.7
Hz, 1H), 3.47 (m, 1H), 7.44 (m, 2H), 7.92 (m, 2H). 13C NMR δ
24.7, 27.9, 34.7, 35.2, 40.3, 74.1, 115.2, 122.7, 125.6 (q), 130.3
(q), 140.4. MS m/ z (relative intensity) 372 (M+, 21.4).
tr a n s-2-Hyd r oxycycloh exyl 2-Th ien yl Tellu r id e (1k ).
Due to some decomposition at room temperature, this com-
pound was directly O-allylated without purification.
tr a n s-2-Hyd r oxy-5-h exen yl p h en yl selen id e (1l): 1H
NMR δ 1.59-1.67 (several peaks, 2H), 2.06-2.27 (several
peaks, 2H), 2.42 (m, 1H), 2.89 (dd, J ) 12.7, 8.5 Hz, 1H), 3.14
(dd, J ) 12.7, 3.6 Hz, 1H), 3.70 (m, 1H), 4.95 (ddt, J ) 10.2,
2.0, 1.2 Hz, 1H), 5.01 (ddt, J ) 17.1, 2.0, 1.6, Hz, 1H), 5.79
(ddt, J ) 17.0, 10.3, 6.6 Hz, 1H), 7.24-7.29 (several peaks,
3H), 7.52 (m, 2H). 13C NMR δ 30.0, 35.6, 37.1, 69.3, 114.9,
127.2, 129.2, 129.3, 132.9, 138.0. MS m/ z (relative intensity)
256 (M+, 16.4).
The following compounds were similarly prepared. As
judged by 1H NMR spectroscopy, the purity of the materials
were > 98%. For yields see Tables 1 and 2.
1
2-Hyd r oxy-5-h exen yl p h en yl tellu r id e (1a ): H NMR δ
1.58-1.69 (several peaks, 2H), 2.05-2.24 (several peaks, 2H),
2.28 (m, 1H), 2.98 (dd, J ) 12.3, 7.9 Hz, 1H), 3.15 (dd, J )
12.3, 4.2 Hz, 1H), 3.74 (m, 1H), 4.95 (ddt, J ) 10.2, 2.0, 1.2
Hz, 1H), 5.00 (ddt, J ) 17.1, 1.9, 1.6 Hz, 1H), 5.78 (ddt, J )
16.9, 10.2, 6.7 Hz, 1H), 7.16-7.22 (several peaks, 3H), 7.74
(m, 2H). 13C NMR δ 20.1, 30.2, 36.8, 70.6, 111.2, 114.9, 127.8,
129.2, 138.0, 138.4. MS m/ z (relative intensity) 306 (M+, 7.5).
2-Hyd r oxy-5-h exen yl 4-(d im eth yla m in o)p h en yl tellu -
r id e (1b): 1H NMR δ 1.58-1.65 (several peaks, 2H), 2.03-
2.23 (several peaks, 2H), 2.30 (d, J ) 4.3 Hz, 1H), 2.82 (dd, J
) 12.2, 8.1 Hz, 1H), 2.94 (s, 6H), 3.02 (dd, J ) 12.2, 4.0 Hz,
1H), 3.68 (m, 1H), 4.93 (ddt, J ) 10.2, 2.0, 1.2 Hz, 1H), 4.99
(dq, J ) 17.2, 1.7 Hz, 1H), 5.78 (ddt, J ) 16.9, 10.2, 6.6 Hz,
1H), 6.55 (m, 2H), 7.64 (m, 2H). 13C NMR δ 20.3, 30.2, 36.7,
40.1, 70.5, 94.0, 113.4, 114.7, 138.2, 141.1, 150.4. MS m/ z
(relative intensity) 349 (M+, 21.7).
2-Hyd r oxy-2-p h en yleth yl P h en yl Selen id e (1m ). 1H
NMR data were in good agreement with literature data.19
3-(Allyloxy)-2-h yd r oxyp r op yl p h en yl selen id e (1n ): 1H
NMR δ 2.66 (d, J ) 4.5 Hz, 1H), 3.03 (dd, J ) 12.7, 7.0 Hz,
1H), 3.10 (dd, J ) 12.8, 5.7 Hz, 1H), 3.47 (dd, J ) 9.6, 5.9 Hz,
1H), 3.53 (dd, J ) 9.6, 4.0 Hz, 1H), 3.92 (m, 1H), 3.96 (dt, J )
5.6, 1.4 Hz, 2H), 5.18 (dddd, J ) 10.4, 1.7, 1.2, 1.2 Hz, 1H),
5.25 (dq, J ) 17.2, 1.6 Hz, 1H), 5.87 (ddt, J ) 17.2, 10.4, 5.6
Hz, 1H), 7.23-7.29 (several peaks, 3H), 7.53 (m, 2H). 13C NMR
δ 31.9, 69.4, 72.3, 72.8, 117.3, 127.2, 129., 129.6, 132.8, 134.3.
MS m/ z (relative intensity) 272 (M+, 18.9).
2-Hyd r oxy-5-h exen yl 4-(tr iflu or om eth yl)p h en yl tel-
lu r id e (1c): 1H NMR δ 1.64-1.70 (several peaks, 2H), 2.09-
2.27 (several peaks, 3H), 3.06 (dd, J ) 12.3, 7.9Hz, 1H), 3.20
(dd, J ) 12.3, 4.1 Hz, 1H), 3.80 (br s, 1H), 4.97 (dm, J ) 10.2
Hz, 1H), 5.02 (dq, J ) 17.1, 1.8 Hz, 1H), 5.80 (ddt, J ) 16.9,
10.2, 6.7 Hz, 1H), 7.43 (m, 2H), 7.81 (m, 2H). 13C NMR δ 20.2,
30.2, 37.1, 70.7, 115.2, 117.0, 125.4, 125.7 (q), 130.0, 137.7,
137.8. MS m/ z (relative intensity) 374 (M+, 18.3).
2-Hyd r oxy-5-h exen yl 2-th ien yl tellu r id e (1d ): 1H NMR
δ 1.61-1.68 (several peaks, 2H), 2.05-2.23 (several peaks, 3H),
2.89 (dd, J ) 12.2, 8.1 Hz, 1H), 3.04 (dd, J ) 12.1, 4.1 Hz,
1H), 3.78 (m, 1H), 4.96 (ddt, J ) 10.2, 2.0, 1.2 Hz, 1H), 5.01
(dq, J ) 17.1, 1.6 Hz, 1H), 5.79 (ddt, J ) 17.1, 10.3, 6.7 Hz,
1H), 6.93 (dd, J ) 5.2, 3.5 Hz, 1H), 7.39 (dd, J ) 3.5, 1.1 Hz,
1H), 7.43 (dd, J ) 5.2, 1.1 Hz, 1H). 13C NMR δ 22.4, 30.2,
36.7, 70.6, 97.0, 115.0, 128.9, 134.3, 138.0, 141.4. MS m/ z
(relative intensity) 312 (M+, 95.7).
1
2-Hyd r oxy-3-p h en oxyp r op yl p h en yl selen id e (1o): H
NMR δ 2.71 (d, J ) 4.8 Hz, 1H), 3.13 (dd, J ) 12.8, 6.8 Hz,
1H), 3.22 (dd, J ) 12.8, 5.6 Hz, 1H), 4.01 (dd, J ) 9.4, 5.8Hz,
1H), 4.04 (dd, J ) 9.3, 4.2 Hz, 1H), 4.13 (m, 1H), 6.84-6.99
(several peaks, 3H), 7.22-7.30 (several peaks, 5H), 7.54 (m,
2H). 13C NMR δ 31.9, 69.1, 70.4, 114.5, 121.2, 127.3, 129.2,
129.5, 132.9, 158.3. MS m/ z (relative intensity) 308 (M+, 18.0).
tr a n s-2-Hyd r oxycycloh exyl P h en yl Selen id e (1q). 1H
NMR data were in good agreement with literature data.19
2-Hyd r oxy-1-p h en yleth yl P h en yl Selen id e (2a ). 1H
NMR data were in good agreement with literature data.19
Typ ica l P r oced u r e for O-Allyla tion of Ar yl â-Hyd r oxy-
a lk yl Tellu r id es a n d Selen id es (1). P r ep a r a tion of 2,3-
Bis(a llyloxy)p r op yl 4-(Tr iflu or om eth yl)p h en yl Tellu r id e
(3g). To a solution of 3-(allyloxy)-2-hydroxypropyl 4-(trifluo-
romethyl)phenyl telluride (1g) (0.40 g, 1.0 mmol) in dry THF
(20 mL) at room temperature was added sodium hydride (0.040
g, 60% dispersion, 1.0 mmol). The resulting mixture was
stirred for ca. 1 h at room temperature. Allyl bromide (0.12 g,
0.089 mL, 1.0 mmol) was then added dropwise, and the
reaction flask was placed in an oil bath preheated to 80 °C.
The mixture was refluxed for 1 h and cooled to room temper-
ature. Water (50 mL) was added, and the solution was
extracted with ether (3 × 30 mL). The combined organic phase
was washed twice with water and with saturated brine and
then dried over Na2SO4. The solvent was removed in vacuo
and the residue was purified by flash chromatography (5%
ether/pentane) to afford 0.32 g (73%) of the title compound as
a light yellow oil. 1H NMR δ 3.19 (dd, J ) 12.0, 6.1 Hz, 1H),
3.26 (dd, J ) 11.9, 5.9 Hz, 1H), 3.51 (dd, J ) 9.9, 5.9 Hz, 1H),
3.61 (dd, J ) 9.8, 4.9 Hz, 1H), 3.80 (ddd, J ) 11.8, 5.9, 4.8 Hz,
1H), 3.97 (dt, J ) 5.7, 1.5 Hz, 2H), 4.06 (ddt, J ) 12.7, 7.0, 1.5
Hz, 1H), 4.11 (ddt, J ) 12.7, 5.7, 1.4 Hz, 1H), 5.16 (ddt, J )
10.2, 1.8, 1.3 Hz, 1H), 5.18 (ddt, J ) 10.3, 1.8, 1.2 Hz, 1H),
5.24 (dq, J ) 17.2, 1.7 Hz, 1H), 5.26 (dq, J ) 17.2, 1.7 Hz,
1H), 5.87 (ddt, J ) 17.2, 10.4, 5.6 Hz, 1H), 5.88 (ddt, J ) 17.3,
10.4, 5.6 Hz, 1H), 7.40 (m, 2H), 7.80 (m, 2H). 13C NMR δ 12.4,
71.0, 72.3, 72.4, 77.5, 117.2, 118.4, 122.8, 125.5 (q), 129.3,
2-H yd r oxyb u t yl 4-(t r iflu or om et h yl)p h en yl t ellu r id e
1
(1e): H NMR δ 0.96 (t, J ) 7.5 Hz, 3H), 1.54-1.67 (several
peaks, 2H), 2.21 (m, 1H), 3.07 (dd, J ) 12.2, 7.8 Hz, 1H), 3.21
(dd, J ) 12.2, 4.0 Hz, 1H), 3.70 (m, 1H), 7.42 (m,2H), 7.81 (m,
2H). 13C NMR δ 10.2, 19.9, 31.0, 72.5, 117.1, 122.7, 125.6 (q),
129.6 (q), 137.6. MS m/ z (relative intensity) 348 (M+, 17.9).
2-Hydr oxy-2-ph en yleth yl 4-(tr iflu or om eth yl)ph en yl tel-
lu r id e (1f): 1H NMR δ 2.50 (d, J ) 3.4 Hz, 1H), 3.33 (dd, J )
12.2, 5.7 Hz, 1H), 3.36 (dd, J ) 12.2, 7.4 Hz, 1H), 4.95 (ddd, J
) 7.2, 5.7, 3.3 Hz, 1H), 7.25-7.41 (several peaks, 7H), 7.73
(m, 2H). 13C NMR δ 20.8, 73.8, 117.2, 125.6 (q), 128.1, 128.6,
137.7, 143.3. MS m/ z (relative intensity) 396 (M+, 15.3).
3-(Allyloxy)-2-h yd r oxyp r op yl 4-(tr iflu or om eth yl)p h e-
1
n yl tellu r id e (1g): H NMR δ 2.75 (d, J ) 3.7 Hz, 1H), 3.11
(dd, J ) 12.1, 5.8 Hz, 1H), 3.16 (dd, J ) 12.1, 6.6 Hz, 1H),
3.45 (dd, J ) 9.5, 6.2 Hz, 1H), 3.53 (dd, J ) 9.5, 3.9 Hz, 1H),
3.97 (dt, J ) 5.7, 1.4 Hz, 2H), 3.99 (m, 1H), 5.19 (dq, J ) 10.4,
1.4 Hz, 1H), 5.25 (dq, J ) 17.2, 1.6 Hz, 1H), 5.87 (ddt, J )
17.2, 10.4, 5.7 Hz, 1H), 7.41 (m, 2H), 7.81 (m, 2H). 13C NMR
δ 14.0, 70.2, 72.3, 73.9, 117.5, 117.7, 122.7, 125.6 (q), 129.5,
134.2, 137.5. MS m/ z (relative intensity) 390 (M+, 31.6).
2-Hyd r oxy-3-p h en oxyp r op yl 4-(tr iflu or om eth yl)p h e-
1
n yl tellu r id e (1h ): H NMR δ 2.67 (d, J ) 5.0 Hz, 1H), 3.25
(d, J ) 6.2 Hz, 2H), 4.00 (dd, J ) 9.3, 5.9 Hz, 1H), 4.04 (dd, J
) 9.3, 4.3 Hz, 1H), 4.22 (m, 1H), 6.82-7.00 (several peaks,
3H), 7.24-7.41 (several peaks, 4H), 7.81 (m, 2H). 13C NMR δ
14.0, 70.0, 71.4, 114.4, 114.5, 121.4, 125.7 (q), 129.5, 137.7,
158.1. MS m/ z (relative intensity) 426 (M+, 15.3).

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 167
134.4, 134.6, 137.3. Anal. Calcd for C16H19F3O2Te: C, 44.91;
H, 4.48. Found: C, 45.37; H, 4.50.
The following compounds were similarly prepared. As
judged by 1H NMR spectroscopy, the purity of the materials
were >98%. For yields see Tables 1 and 2.
(m, 1H), 3.49 (ddd, J ) 11.7, 10.0, 3.9 Hz, 1H), 3.95 (ddt, J )
12.6, 5.6, 1.6 Hz, 1H), 4.15 (ddt, J ) 12.6, 5.6, 1.4 Hz, 1H),
5.18 (ddt, J ) 10.4, 1.8, 1.3 Hz, 1H), 5.30 (dq, J ) 17.2, 1.7
Hz, 1H), 5.95 (ddt, J ) 17.2, 10.3, 5.6 Hz, 1H), 6.94 (dd, J )
5.1, 3.4 Hz, 1H), 7.36 (dd, J ) 3.4, 1.1 Hz, 1H), 7.43 (dd, J )
5.2, 1.1 Hz, 1H). 13C NMR δ 24.2, 27.6, 32.6, 33.4, 69.7, 82.9,
97.3, 116.8, 128.9, 134.7, 134.9, 142.8.
2-(Allyloxy)-5-h exen yl p h en yl selen id e (3l): 1H NMR
δ 1.64-1.81 (several peaks, 2H), 2.04-2.22 (several peaks, 2H),
2.99 (dd, J ) 12.3, 6.6 Hz, 1H), 3.11 (dd, J ) 12.3, 5.2 Hz,
1H), 3.53 (ddt, J ) 7.1, 6.7, 5.0 Hz, 1H), 3.92 (ddt, J ) 12.4,
5.7, 1.3 Hz, 1H), 4.04 (ddt, J ) 12.5, 5.6, 1.3 Hz, 1H), 4.95
(ddt, J ) 10.1, 2.0, 1.3 Hz, 1H), 5.00 (ddt, J ) 17.1, 1.9, 1.6
Hz, 1H), 5.13 (ddt, J ) 10.3, 1.8, 1.2 Hz, 1H), 5.21 (dq, J )
17.1, 1.6 Hz, 1H), 5.78 (ddt, J ) 17.0, 10.5, 6.5 Hz, 1H), 5.88
(ddt, J ) 17.2, 10.3, 5.7 Hz, 1H), 7.22-7.28 (several peaks,
3H), 7.51 (m, 2H). 13C NMR δ 29.5, 32.2, 33.5, 70.4, 77.8,
114.8, 116.9, 126.8, 129.0, 130.6, 132.7, 134.9, 138.2.
2-(Allyloxy)-2-p h en ylet h yl p h en yl selen id e (3m ): 1H
NMR δ 3.11 (dd, J ) 12.3, 5.2 Hz, 1H), 3.36 (dd, J ) 12.2, 8.3
Hz, 1H), 3.79 (ddt, J ) 12.7, 6.0, 1.3 Hz, 1H), 3.94 (dddd, J )
12.7, 5.1, 1.7, 1.4 Hz, 1H), 4.53 (dd, J ) 8.3, 5.2 Hz, 1H), 5.15
(ddt, J ) 10.1, 1.9, 1.3 Hz, 1H), 5.23 (dq, J ) 17.2, 1.7 Hz,
1H), 5.88 (dddd, J ) 17.2, 10.3, 6.1, 5.0 Hz, 1H), 7.19-7.36
(several peaks, 8H), 7.46 (m, 2H). 13C NMR δ 35.4, 69.8, 80.7,
117.0, 118.7, 126.6, 128.0, 128.5, 128.9, 130.8, 132.5, 134.5,
141.1.
2-[(3-Meth yl-2-bu ten yl)oxy]-2-p h en yleth yl p h en yl se-
len id e (3m ′): 1H NMR δ 1.53 (m, 3H), 1.71 (m, 3H), 3.09 (dd,
J ) 12.2, 5.3 Hz, 1H), 3.34 (dd, J ) 12.2, 8.3 Hz, 1H), 3.79 (m,
1H), 3.88 (m, 1H), 4.49 (dd, J ) 8.3, 5.3 Hz, 1H), 5.35 (m, 1H),
7.20-7.36 (several peaks, 8H), 7.47 (m, 2H). 13C NMR δ 18.0,
25.8, 35.5, 65.4, 80.4, 120.9, 126.6, 126.7, 127.9, 128.4, 128.9,
130.8, 132.5, 137.4, 141.4.
2,3-Bis(a llyloxy)p r op yl p h en yl selen id e (3n ): 1H NMR
δ 3.09 (dd, J ) 12.6, 5.8 Hz, 1H), 3.15 (dd, J ) 12.7, 6.3 Hz,
1H), 3.58 (d, J ) 4.9 Hz, 2H), 3.72 (m, 1H), 3.96 (m, 2H), 4.07
(dt, J ) 5.7, 1.5 Hz, 2H), 5.12-5.19 (several peaks, 2H), 5.22
(dq, J ) 17.2, 1.6 Hz, 1H), 5.25 (dq, J ) 17.2, 1.6 Hz, 1H),
5.82-5.94 (several peaks, 2H), 7.20-7.28 (several peaks, 3H),
7.52 (m, 2H). 13C NMR δ 29.2, 71.0, 71.2, 72.2, 77.3, 116.9,
117.1, 126.7, 128.9, 130.5, 132.4, 134.5, 134.7.
2-(Allyloxy)-3-p h en oxyp r op yl p h en yl selen id e (3o): 1H
NMR δ 3.18 (dd, J ) 12.8, 5.8 Hz, 1H), 3.24 (dd, J ) 12.7, 6.4
H, 1H), 3.91 (ddt, J ) 6.3, 5.8, 4.9 Hz, 1H), 4.09-4.14 (several
peaks, 4H), 5.15 (ddt, J ) 10.3, 1.8, 1.2 Hz, 1H), 5.23 (dq, J )
17.2, 1.7 Hz, 1H), 5.89 (ddt, J ) 17.1, 10.3, 5.7 Hz, 1H), 6.85-
6.98 (several peaks, 3H), 7.20-7.29 (several peaks, 5H), 7.52
(m, 2H). 13C NMR δ 29.3, 69.0, 71.3, 76.8, 114.6, 117.4, 120.9,
126.9, 129.1, 129.39, 129.43, 132.6, 134.6, 158.5.
2-[(3-Meth yl-2-bu ten yl)oxy]-3-p h en oxyp r op yl p h en yl
selen id e (3o′): 1H NMR δ 1.61 (m, 3H), 1.72 (m, 3H), 3.17
(dd, J ) 12.7, 5.9 Hz, 1H), 3.23 (dd, J ) 12.7, 6.2 Hz, 1H),
3.88 (m, 1H), 4.10 (d, J ) 5.1 Hz, 2H), 4.12 (m, 2H), 5.33 (dddt,
J ) 9.8, 7.3, 3.0, 1.2 Hz, 1H), 6.85-6.97 (several peaks, 3H),
7.20-7.29 (several peaks, 5H), 7.52 (m, 2H). 13C NMR δ 18.0,
25.8, 29.4, 66.8, 69.1, 76.3, 114.5, 120.8, 120.9, 126.8, 129.0,
129.3, 129.4, 132.5, 137.5, 158.6.
2-(Allyloxy)-3-(b en zyloxy)p r op yl p h en yl selen id e
(3p ): 1H NMR δ 3.10 (dd, J ) 12.6, 5.8 Hz, 1H), 3.15 (dd, J )
12.5, 6.1 Hz, 1H), 3.60 (dd, J ) 10.0, 5.1 Hz, 1H), 3.63 (dd, J
) 10.0, 4.7 Hz, 1H), 3.74 (m, 1H), 4.06 (dt, J ) 5.7, 1.6 Hz,
2H), 4.50 (s, 2H), 5.13 (dddd, J ) 10.3, 1.7, 1.2, 1.2 Hz, 1H),
5.21 (dq, J ) 17.2, 1.6 Hz, 1H), 5.87 (ddt, J ) 17.1, 10.3, 5.6
Hz, 1H), 7.19-7.36 (several peaks, 8H), 7.50 (m, 2H). 13C NMR
δ 29.4, 71.1, 71.3, 73.3, 77.5, 117.1, 126.8, 127.5, 127.6, 128.3,
129.0, 130.6, 132.5, 134.8, 138.1.
2-(Allyloxy)-1-p h en yleth yl p h en yl selen id e (2b): 1H
NMR δ 3.86 (dd, J ) 10.3, 6.1 Hz, 1H), 3.95 (m, 2H), 3.98 (dd,
J ) 10.2, 8.3 Hz, 1H), 4.49 (dd, J ) 8.3, 6.0 Hz, 1H), 5.12 (dddd,
J ) 10.3, 1.7, 1.2, 1.2 Hz, 1H), 5.18 (dddd, J ) 17.2, 1.7, 1.5,
1.5 Hz, 1H), 5.81 (ddt, J ) 17.2, 10.3, 5.5 Hz, 1H), 7.16-7.28
(several peaks, 8H), 7.44 (m, 2H). 13C NMR δ 47.4, 72.0, 72.9,
117.2, 127.2, 127.8, 128.0, 128.4, 128.8, 129.1, 134.5, 135.2.
2-[(3-Meth yl-2-bu ten yl)oxy]-1-p h en yleth yl p h en yl se-
len id e (2c): 1H NMR δ 1.57 (m, 3H), 1.69 (m, 3H), 3.84 (dd, J
) 10.3, 6.1 Hz, 1H), 3.93 (m, 2H), 3.96 (dd, J ) 10.4, 8.5 Hz,
1H), 4.49 (dd, J ) 8.4, 6.1 Hz, 1H), 5.25 (tq, J ) 7.0, 1.4 Hz,
1H), 7.16-7.27 (several peaks, 8H), 7.43 (m, 2H). 13C NMR δ
17.9, 25.7, 47.4, 67.3, 72.5, 120.9, 127.1, 128.0, 128.3, 128.8,
129.1, 135.2, 137.1, 140.0.
2-(Allyloxy)-5-h exen yl 2-th ien yl tellu r id e (3d ): 1H NMR
δ 1.73(m, 2Η), 2.11(m, 2Η), 3.03(dd, J ) 11.8, 6.0 Hz, 1H),
3.07 (dd, J ) 11.8, 5.4 Hz, 1H), 3.55 (m, 1H), 3.92 (m, 2H),
4.00 (m, 2H), 4.96 (dm, J ) 1.2 Hz, 1H), 5.01 (dm, J ) 17.2
Hz, 1H), 5.15 (dm, J ) 10.2 Hz, 1H), 5.23 (dq, J ) 17.2, 1.6
Hz, 1H), 5.84 (m, 2H), 6.93 (dd, J ) 5.1, 3.4 Hz, 1H), 7.38 (dd,
J ) 3.4, 1.1 Hz, 1H), 7.42 (dd, J ) 5.1, 1.1 Hz, 1H). 13C NMR
17.8, 29.6, 34.4, 70.1, 78.2, 97.8, 114.8, 116.9, 128.8, 134.1,
134.9, 138.1, 141.2.
2-(Allyloxy)bu tyl 4-(tr iflu or om eth yl)p h en yl tellu r id e
(3e): 1H NMR δ 0.93 (t, J ) 7.4 Hz, 3H), 1.57-1.76 (several
peaks, 2H), 3.17 (dd, J ) 11.7, 5.7 Hz, 1H), 3.21 (dd, J ) 11.7,
6.0 Hz, 1H), 3.53 (dt, J ) 11.8, 5.9 Hz, 1H), 4.00 (ddd, J ) 5.6,
1.6, 1.3 Hz, 2H), 5.15 (ddt, J ) 10.3, 1.8, 1.3 Hz, 1H), 5.24 (dq,
J ) 17.2, 1.7 Hz, 1H), 5.89 (ddt, J ) 17.2, 10.4, 5.6 Hz, 1H),
7.41 (m, 2H), 7.80 (m, 2H). 13C NMR δ 9.6, 15.2, 28.1, 70.2,
80.0, 116.9, 118.0, 122.8, 125.5 (q), 129.5 (q), 134.8, 137.5.
2-(Allyloxy)-2-p h en yleth yl 4-(tr iflu or om eth yl)p h en yl
tellu r id e (3f): 1H NMR δ 3.17 (dd, J ) 11.7, 5.2 Hz, 1H),
3.49 (dd, J ) 11.7, 8.7 Hz, 1H), 3.79 (ddt, J ) 12.7, 6.0 Hz,
1H), 3.94 (dddd, J ) 12.7, 5.1, 1.7, 1.4 Hz, 1H), 4.66 (dd, J )
8.8, 5.1 Hz, 1H), 5.16 (ddt, J ) 10.4, 1.8, 1.3 Hz, 1H), 5.23 (dq,
J ) 17.2, 1.7 Hz, 1H), 5.88 (dddd, J ) 17.3, 10.5, 6.1, 5.0 Hz,
1H), 7.27-7.38 (several peaks, 7H), 7.71 (m, 2H). 13C NMR δ
18.1, 69.9, 81.6, 117.1, 118.4, 122.8, 125.4 (q), 126.4, 128.1,
128.6, 134.4, 137.4, 141.7.
2-(Allyloxy)-3-p h en oxyp r op yl 4-(tr iflu or om eth yl)p h e-
n yl tellu r id e (3h ): 1H NMR δ 3.26 (dd, 12.3, 5.8 Hz, 1H),
3.37 (dd, J ) 12.4, 5.6 Hz, 1H), 3.96-4.20 (several peaks, 5H),
5.18 (dq, J ) 10.4, 1.4 Hz, 1H), 5.26 (dq, J ) 17.2, 1.7 Hz,
1H), 5.89 (ddt, J ) 17.1, 10.5, 5.6 Hz, 1H), 6.83-6.88 (several
peaks, 2H), 6.94 (m, 1H), 7.26 (m, 2H), 7.78 (m, 2H). 13C NMR
δ 12.2, 69.9, 71.3, 77.3, 114.4, 114.6, 117.5, 121.0, 121.1, 125.6
(q), 129.4 (q), 134.4, 137.6, 158.3.
2-(Allyloxy)-3-(ben zyloxy)p r op yl 4-(tr iflu or om eth yl)-
p h en yl tellu r id e (3i): 1H NMR δ 3.19 (dd, J ) 11.9, 6.0 Hz,
1H), 3.26 (dd, J ) 11.9, 5.8 Hz, 1H), 3.55 (dd, J ) 9.8, 5.8 Hz,
1H), 3.65 (dd, J ) 9.8, 4.8 Hz, 1H), 3.82 (ddd, J ) 11.7, 5.9,
4.8 Hz, 1H), 4.04 (ddt, J ) 12.7, 5.7, 1.5 Hz, 1H), 4.09 (ddt, J
) 12.6, 5.7, 1.6 Hz, 1H), 4.51 (s, 2H), 5.15 (ddt, J ) 10.4, 1.8,
1.3 Hz, 1H), 5.23 (dq, J ) 17.2, 1.6 Hz, 1H), 5.87 (ddt, J )
17.1, 10.3, 5.6 Hz, 1H), 7.26-7.40 (several peaks, 7H), 7.78
(m, 2H). 13C NMR δ 12.4, 71.0, 72.4, 73.4, 77.6, 117.2, 118.4,
125.5 (q), 127.6, 127.7, 128.4, 134.6, 137.3, 137.9.
tr a n s-2-(Allyloxy)cycloh exyl 4-(tr iflu or om eth yl)p h e-
n yl tellu r id e (3j): 1H NMR δ 1.15-1.36 (several peaks, 3H),
1.51-1.63 (several peaks, 2H), 1.81 (m, 1H), 1.95 (m, 1H), 2.14
(m, 1H), 3.42 (m, 1H), 3.64 (ddd, J ) 11.3, 9.7, 3.9 Hz, 1H),
3.94 (ddt, J ) 12.5, 5.6, 1.5 Hz, 1H), 4.14 (ddt, J ) 12.5, 5.6,
1.4 Hz, 1H), 5.16 (ddt, J ) 10.4, 1.8, 1.3 Hz, 1H), 5.27 (dq, J
) 17.1, 1.7 Hz, 1H), 5.90 (ddt, J ) 17.2, 10.3, 5.6 Hz, 1H),
7.41 (m, 2H), 7.91 (m, 2H). 13C NMR δ 24.0, 27.6, 32.4, 33.3,
34.0, 69.7, 82.8, 116.8, 122.8, 125.3 (q), 125.5, 129.7 (q), 134.9,
140.4.
3-(Ben zyloxy)-2-[(3-m eth yl-2-bu ten yl)oxy]pr opyl ph en -
yl selen id e (3p ′): 1H NMR δ 1.61 (m, 3H), 1.71 (m, 3H), 3.09
(dd, J ) 12.5, 5.9 Hz, 1H), 3.16 (dd, J ) 12.5, 6.0 Hz, 1H),
3.59 (dd, J ) 9.9, 5.3 Hz, 1H), 3.62 (dd, J ) 9.9, 4.7 Hz, 1H),
3.71 (m, 1H), 4.05 (m, 2H), 4.50 (s, 2H), 5.31 (dtt, J ) 6.9, 2.8,
1.4 Hz, 1H), 7.18-7.35 (several peaks, 8H), 7.50 (m, 2H). 13C
NMR δ 18.0, 25.7, 29.6, 66.5, 71.5, 73.3, 77.1, 121.1, 126.7,
127.5, 127.6, 128.3, 129.0, 132.4, 137.0.
tr a n s-2-(Allyloxy)cycloh exyl 2-th ien yl tellu r id e (3k ):
1H NMR δ 1.09-1.32 (several peaks, 3H), 1.41-1.58 (several
peaks, 2H), 1.73-1.83 (several peaks, 2H), 2.14 (m, 1H), 3.37

168 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
2-(Allyloxy)cycloh exyl p h en yl selen id e (3q): 1H NMR
δ 1.21-1.43 (m, 3H), 1.45-1.55 (m, 1H), 1.56-1.64 (m, 1H),
1.69-1.77 (m, 1H), 1.98-2.06 (m, 1H), 2.07-2.14 (m, 1H),
3.28-3.38 (m, 2H), 3.99 (ddt, J ) 12.6, 5.6, 1.5 Hz, 1H), 4.10
(ddt, J ) 12.6, 5.7, 1.5z, 1H), 5.15 (ddt, J ) 10.4, 1.9, 1.3 Hz,
1H), 5.27 (dq, J ) 17.2, 1.7 Hz, 1H), 5.92 (ddt, J ) 17.2, 10.3,
5.6 Hz, 1H), 7.22-7.27 (m, 3H), 7.56-7.60 (m, 2H). 13C NMR
δ 23.5, 25.6, 31.1, 32.0, 47.5, 70.0, 80.4, 116.7, 127.2, 128.7,
129.2, 135.0, 135.2.
Typ ica l P r oced u r e for O-P r op -2-yn yla tion of â-Hy-
d r oxya lk yl Ar yl Tellu r id es a n d Selen id es. P r ep a r a tion
of tr a n s-2-(2-P r op yn yloxy)cycloh exyl P h en yl Selen id e
(4q). To a solution of 2-hydroxycyclohexyl phenyl selenide
(1.77 g, 6.96 mmol) in dry THF (50 mL) was added sodium
hydride (0.28 g, 60% dispersion, 6.96 mmol), and the resulting
mixture was stirred for 2 h at room temperature. Propargyl
bromide (80% in toluene, 0.77 mL, 6.96 mmol) was added
dropwise and the mixture stirred for 6 h after which TLC
showed the complete consumption of the starting material.
Water (50 mL) was added and the solution extracted with
ether (3 × 30 mL). The combined ether extracts were washed
twice with water and with brine and dried over Na2SO4. The
solvent was removed in vacuo and the residue on purification
by flash chromatography (5% ether/pentane) afforded 1.55 g
(77%) of the title compound. 1H NMR δ 1.18-1.44 (several
peaks, 3H), 1.51 (m, 1H), 1.60 (m, 1H), 1.73 (m, 1H), 2.04 (m,
1H), 2.16 (m, 1H), 2.40 (t, J ) 2.4 Hz, 1H), 3.29 (ddd, J ) 9.8,
8.3, 4.2 Hz, 1H), 3.54 (ddd, J ) 8.5, 8.5, 3.7 Hz, 1H), 4.20 (dd,
J ) 15.8, 2.4 Hz, 1H), 4.27 (dd, J ) 15.9, 2.5 Hz, 1H), 7.22-
7.28 (several peaks, 3H), 7.60 (m, 2H). 13C NMR δ 23.3, 25.4,
30.7, 31.9, 47.2, 56.2, 74.0, 79.9, 80.2, 127.3, 128.8, 129.1, 135.0.
Anal. Calcd for C15H18OSe: C, 61.43; H, 6.19. Found: C,
61.56; H, 6.18.
The following compounds were obtained by allyloxysele-
nenation of vinylic ethers.
2-(Allyloxy)-2-eth oxyeth yl P h en yl Selen id e (14a ). Ex-
cept that triethylamine was used as a base instead of diiso-
propylamine, this compound was prepared according to a
literature procedure39 in 58% yield. 1H NMR δ 1.19 (t, J )
7.1 Hz, 3H), 3.11 (dd, J ) 12.5, 5.7 Hz, 1H), 3.14 (dd, J ) 12.5,
5.7 Hz, 1H), 3.54 (dq, J ) 9.4, 7.0 Hz, 1H), 3.66 (dq, J ) 9.3,
7.0 Hz, 1H), 4.12 (ddt, J ) 12.7, 5.4, 1.4 Hz, 1H), 4.14 (ddt, J
) 12.7, 5.8, 1.4 Hz, 1H), 4.76 (t, J ) 5.7 Hz, 1H), 5.16 (ddt, J
) 10.4, 1.8, 1.3 Hz, 1H), 5.27 (dq, J ) 17.1, 1.6 Hz, 1H), 5.90
(dddd, J ) 17.2, 10.4, 5.8, 5.5 Hz, 1H), 7.21-7.28 (several
peaks, 3H), 7.52 (m, 2H). 13C NMR δ 15.2, 30.9, 61.9, 67.1,
101.8, 117.0, 126.9, 129.0, 130.3, 132.6, 134.3. MS m/ z
(relative intensity) 286 (M+, 5.5).
The following compounds were similarly prepared. As
judged by 1H NMR spectroscopy, the purity of the materials
were >98%. For yields see Tables 1 and 2.
2-(Allyloxy)-2-n -b u t oxyet h yl P h en yl Selen id e (14b ).
Except that triethylamine was used as a base instead of
diisopropylamine, this compound was prepared according to
a literature procedure39 in 74% yield. 1H NMR δ 0.91 (t, J )
7.3 Hz, 3H), 1.31-1.42 (several peaks, 2H), 1.50-1.58 (several
peaks, 2H), 3.10 (dd, J ) 12.5, 5.6 Hz, 1H), 3.14 (dd, J ) 12.5,
5.7 Hz, 1H), 3.46 (dt, J ) 9.3, 6.5 Hz, 1H), 3.59 (dt, J ) 9.2,
6.5 Hz, 1H), 4.03 (ddt, J ) 12.8, 5.9, 1.5 Hz, 1H), 4.12 (ddt, J
) 12.7, 5.4, 1.5 Hz, 1H), 4.76 (t, J ) 5.7 Hz, 1H), 5.16 (ddt, J
) 10.4, 1.7, 1.3 Hz, 1H), 5.27 (dq, J ) 17.2, 1.7 Hz, 1H), 5.89
(ddt, J ) 17.2, 10.4, 5.7 Hz, 1H), 7.19-7.27 (several peaks,
3H), 7.52 (m, 2H). 13C NMR δ 13.8, 19.3, 30.9, 31.8, 66.1, 67.0,
101.8, 116.9, 126.8, 128.9, 130.4, 132.5, 134.4. MS m/ z
(relative intensity) 314 (M+, 5.0).
2-(Allyloxy)-2-ter t-bu toxyeth yl P h en yl Selen id e (14c).
Except that phenylselenenyl chloride instead of phenylsele-
nenyl bromide was used as selenenating agent, and pyridine
was used as a base instead of diisopropylamine, this compound
was prepared according to a literature procedure39 in 65%
yield. 1H NMR δ 1.12 (s, 9H), 3.08 (dd, J ) 12.3, 6.1 Hz, 1H),
3.12 (dd, J ) 12.3, 5.3 Hz, 1H), 4.02 (ddt, J ) 12.6, 5.4, 1.5
Hz, 1H), 4.06 (ddt, J ) 12.6, 5.5, 1.5 Hz, 1H), 4.99 (dd, J )
6.0, 5.3 Hz, 1H), 5.13 (ddt, J ) 10.4, 1.8, 1.4 Hz, 1H), 5.26 (dq,
J ) 17.2, 1.8 H, 1H), 5.89 (ddt, J ) 17.3, 10.4, 5.5 Hz, 1H),
7.18-7.26 (several peaks, 3H), 7.51 (several peaks, 2H). 13C
NMR δ 28.7, 32.4, 64.3, 74.7, 96.4, 116.4, 126.7, 128.9, 130.7,
132.4, 134.8. MS m/ z (relative intensity) 314 (M+, 1.0).
2-(2-P r op yn yloxy)-5-h exen yl 4-(tr iflu or om eth yl)p h e-
n yl tellu r id e (4c): 1H NMR δ 1.65-1.83 (several peaks, 2H),
2.10-2.18 (several peaks, 2H), 2.40 (t, J ) 2.4 Hz, 1H), 3.17
(dd, J ) 12.1, 5.6 Hz, 1H), 3.22 (dd, J ) 12.0, 6.6 Hz, 1H),
3.77 (m, 1H), 4.17 (d, J ) 2.4 Hz, 2H), 4.97 (dm, J ) 10.2 Hz,
1H), 5.01 (dq, J ) 17.0, 1.6 Hz, 1H), 5.79 (ddt, J ) 17.0, 10.3,
6.6 Hz, 1H), 7.42 (m, 2H), 7.82 (m, 2H). 13C NMR δ 14.7, 29.4,
34.5, 56.4, 74.5, 77.9, 79.8, 114.9, 115.1, 117.6, 125.6 (q), 128.3,
135.9 (q), 137.8.
2-(2-P r op yn yloxy)bu tyl 4-(tr iflu or om eth yl)p h en yl tel-
lu r id e (4e): 1H NMR (300 MHz) δ 0.93 (t, J ) 7.4 Hz, 3H),
1.50-1.74 (several peaks, 2H), 2.40 (t, J ) 2.3 Hz, 1H), 3.18
(d, J ) 5.8 Hz, 2H), 3.71 (m, 1H), 4.18 (d, J ) 1.7 Hz, 2H),
7.41 (m, 2H), 7.81 (m, 2H). 13C NMR δ 9.5, 14.4, 27.9, 56.4,
74.4, 79.7, 125.6, 137.7.
2-(2-P r op yn yloxy)-2-p h en yleth yl 4-(tr iflu or om eth yl)-
p h en yl tellu r id e (4f): 1H NMR δ 2.35 (t, J ) 2.4 Hz, 1H),
3.12 (dd, J ) 11.8, 5.6 Hz, 1H), 3.41 (dd, J ) 11.7, 8.3 Hz,
1H), 3.80 (dd, J ) 15.8, 2.4 Hz, 1H), 4.07 (dd, J ) 15.8, 2.4
Hz, 1H), 4.79 (dd, J ) 8.3, 5.6 Hz, 1H), 7.15-7.35 (several
peaks, 7H), 7.64 (m, 2H). 13C NMR δ 17.2, 55.9, 74.7, 79.3,
80.9, 118.1, 125.4 (q), 125.7, 126.9, 128.4 (q), 128.7, 137.6,
140.3.
3-(Allyloxy)-2-(2-p r op yn yloxy)p r op yl 4-(tr iflu or om eth -
yl)p h en yl tellu r id e (4g): 1H NMR δ 2.41 (t, J ) 2.4 Hz, 1H),
3.19 (dd, J ) 12.0, 5.8 Hz, 1H), 3.24 (dd, J ) 12.2, 6.2 Hz,
1H), 3.55 (dd, J ) 9.9, 5.2 Hz, 1H), 3.64 (dd, J ) 9.9, 4.9 Hz,
1H), 3.96 (dt, J ) 5.6, 1.6 Hz, 2H), 4.01 (m, 1H), 4.25 (dd, J )
17.2, 2.0 Hz, 1H), 4.29 (dd, J ) 16.8, 2.0 Hz, 1H), 5.19 (dm, J
) 10.4 Hz, 1H), 5.25 (dq, J ) 17.2, 1.7 Hz, 1H), 5.87 (ddt, J )
17.3, 10.5, 5.7 Hz, 1H), 7.41 (m, 2H), 7.81 (m, 2H). 13C NMR
δ 11.4, 57.2, 72.2, 72.3, 74.7, 77.3, 79.7, 117.3, 118.2, 125.5
(q), 134.3, 136.0 (q), 137.4, 138.0.
5-(P h en ylselen o)-3,4-d ih yd r o-2H-p yr a n (16) was iso-
lated in 68% yield by treatment of 3,4-dihydro-2H-pyran with
phenylselenenyl bromide, allyl alcohol, and triethylamine/
diisopropylamine following the literature procedure for the
preparation of compound 17.39 1H NMR δ 1.93-1.99 (several
peaks, 2H), 2.24-2.28 (several peaks, 2H), 4.01-4.05 (several
peaks, 2H), 6.94 (t, J ) 1.7 Hz, 1H), 7.16-7.27 (several peaks,
3H), 7.39 (m, 2H). 13C NMR δ 23.8, 27.2, 65.3, 101.3, 126.1,
129.0, 129.8, 131.6, 150.6. MS m/ z (relative intensity) 240
(M+, 84.6).
3-P h en oxy-2-(2-p r op yn yloxy)p r op yl 4-(tr iflu or om eth -
yl)p h en yl tellu r id e (4h ): 1H NMR δ 2.44 (t, J ) 2.4 Hz, 1H),
3.27 (dd, J ) 12.5, 5.6 Hz, 1H), 3.36 (dd, J ) 12.4, 6.0 Hz,
1H), 4.07 (dd, J ) 9.5, 5.3 Hz, 1H), 4.13-4.23 (several peaks,
2H), 4.32 (dd, J ) 2.4, 1.0 Hz, 1H), 4.47 (m, 1H), 6.82-6.98
(several peaks, 3H), 7.23-7.38 (several peaks, 4H), 7.79 (m,
2H). 13C NMR δ 11.4, 57.4, 69.6, 74.9, 76.8, 79.5, 114.4, 114.5,
121.0, 121.2, 125.5 (q), 129.4, 137.6, 158.1.
tr a n s-2-(Allyloxy)-3-(p h en ylselen o)t et r a h yd r op yr a n
(17). Except that phenylselenenyl chloride was used as a
selenenating agent and triethylamine was used as a base
instead of diisopropylamine, this compound was prepared
according to a literature procedure39 in 54% yield. 1H NMR δ
1.53 (m, 1H), 1.73 (m, 1H), 1.83 (m, 1H), 2.24 (m, 1H), 3.33
(dt, J ) 7.3, 4.4 Hz, 1H), 3.54 (m, 1H), 3.91 (m, 1H), 4.01 (ddt,
J ) 12.9, 6.1, 1.4 Hz, 1H), 4.25 (dddd, J ) 12.9, 5.2, 1.4 Hz,
1H), 4.67 (d, J ) 4.8 Hz, 1H), 5.16 (ddt, J ) 10.4, 1.8, 1.3 Hz,
1H), 5.28 (dq, J ) 17.2, 1.7 Hz, 1H), 5.90 (dddd, J ) 17.2, 10.4,
6.0, 5.2 Hz, 1H), 7.22-7.28 (several peaks, 3H), 7.57 (m, 2H).
13C NMR δ 24.1, 27.2, 44.2, 62.7, 68.6, 101.1, 117.0, 127.5,
128.9, 129.0, 134.2, 134.6. MS m/ z (relative intensity) 298
(M+, 12.4).
3-(Ben zyloxy)-2-(2-p r op yn yloxy)p r op yl 4-(tr iflu or om -
eth yl)p h en yl tellu r id e (4i): 1H NMR δ 2.41 (t, J ) 2.4 Hz,
1H), 3.19 (dd, J ) 12.0, 5.8 Hz, 1H), 3.24 (dd, J ) 12.1, 6.1
Hz, 1H), 3.59 (dd, J ) 9.9, 5.3 Hz, 1H), 3.68 (dd, J ) 10.0, 5.0
Hz, 1H), 4.02 (tt, J ) 10.2, 6.0 Hz, 1H), 4.24 (dd, J ) 15.9, 2.5
Hz, 1H), 4.29 (dd, J ) 15.9, 2.4 Hz, 1H), 4.50 (s, 2H), 7.27-

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 169
7.41 (m, 7H), 7.77-7.82 (m, 2H). 13C NMR δ 11.5, 57.2, 72.3,
73.5, 74.7, 77.4, 79.7, 118.2, 125.5, 127.7, 127.8, 128.4, 137.4,
137.8.
1H), 4.18 (dd, J ) 9.1, 7.4 Hz, 1H), 7.43 (m, 2H), 7.80 (m, 2H).
1H NMR endo-6j δ 1.10-1.99 (several peaks, 9H), 2.72 (m, 1H),
2.90 (dd, J ) 11.5, 7.7 Hz, 1H), 2.99 (dd, J ) 11.5, 8.5 Hz,
1H), 3.53 (dd, J ) 9.9, 8.1 Hz, 1H), 3.95-4.05 (several peaks,
2H), 7.43 (m, 2H), 7.80 (m, 2H). 13C NMR exo+endo δ 6.0,
13.6, 20.3, 20.9, 21.6, 23.6, 24.2, 27.4, 28.2, 28.5, 41.6, 45.3,
45.8, 45.8, 72.0, 73.9, 76.4, 78.4, 116.9, 122.7, 125.7 (q), 129.8
(q), 137.8. Anal. Calcd for C16H19F3OTe: C, 46.65; H, 4.65.
Found: C, 46.86; H, 4.68. MS m/ z (relative intensity) 414
(M+, 9.6).
tr a n s-2-(2-P r op yn yloxy)cycloh exyl 4-(tr iflu or om eth -
yl)p h en yl tellu r id e (4j): 1H NMR δ 1.17-1.38 (several
peaks, 3H), 1.51-1.67 (several peaks, 2H), 1.80 (m, 1H), 2.01
(m, 1H), 2.18 (m, 1H), 2.42 (t, J ) 2.4 Hz, 1H), 3.55-3.65
(several peaks, 2H), 4.17 (dd, J ) 15.8, 2.4 Hz, 1H), 4.26 (dd,
J ) 15.9, 2.4 Hz, 1H), 7.40-7.44 (m, 2H), 7.91-7.94 (m, 2H).
13C NMR (300 MHz) δ 23.8, 27.5, 31.9, 32.8, 33.9, 55.7, 74.4,
81.9, 125.3 (q), 140.3.
The following compounds were similarly prepared. As
judged by 1H NMR spectroscopy, the purity of the materials
were >98%. For yields and cis/ trans-, E/ Z-, and syn/ anti-
ratios see Table 1.
1
2-(2-P r op yn yloxy)-5-h exen yl p h en yl selen id e (4l): H
NMR δ 1.66-1.81 (several peaks, 2H), 2.05-2.23 (several
peaks, 2H), 2.38 (t, J ) 2.4 Hz, 1H), 3.02 (dd, J ) 12.4, 6.6
Hz, 1H), 3.12 (dd, J ) 12.5, 5.0 Hz, 1H), 3.72 (ddt, J ) 13.6,
6.9, 4.9 Hz, 1H), 4.14 (dd, J ) 15.8, 2.4 Hz, 1H), 4.19 (dd, J )
15.8, 2.4 Hz, 1H), 4.95 (ddt, J ) 10.2, 2.0, 1.2 Hz, 1H), 5.01
(ddt, J ) 17.1, 2.0, 1.6 Hz, 1H), 5.79 (ddt, J ) 17.1, 10.4, 6.5
Hz, 1H), 7.22-7.29 (several peaks, 3H), 7.53 (m, 2H). 13C NMR
δ 29.4, 31.8, 33.2, 56.6, 74.2, 77.6, 80.0, 114.9, 126.9, 129.0,
130.4, 132.7, 138.0.
2-P h en yl-2-(2-p r op yn yloxy)et h yl p h en yl selen id e
(4m ): 1H NMR δ 2.39 (t, J ) 2.3 Hz, 1H), 3.14 (dd, J ) 12.2,
5.8 Hz, 1H), 3.37 (dd, J ) 12.4, 7.9 Hz, 1H), 3.88 (dd, J ) 15.7,
2.3 Hz, 1H), 4.14 (dd, J ) 15.7, 2.4 Hz, 1H), 4.73 (dd, J ) 7.9,
5.6 Hz, 1H), 7.20-7.37 (several peaks, 8H), 7.48 (m, 2H). 13C
NMR δ 34.8, 55.9, 74.5, 79.5, 80.0, 126.8, 127.0, 128.4, 128.6,
128.9, 130.5, 132.7, 139.8.
3-(Allyloxy)-2-(2-p r op yn yloxy)p r op yl p h en yl selen id e
(4n ): 1H NMR δ 2.39 (t, J ) 2.4 Hz, 1H), 3.11 (dd, J ) 12.7,
5.9 Hz, 1H), 3.15 (dd, J ) 12.7, 6.3 Hz, 1H), 3.61 (d, J ) 4.8
Hz, 2H), 3.92 (tt, J ) 6.1, 4.8 Hz, 1H), 3.94 (dt, J ) 5.6, 1.4
Hz, 2H), 4.24 (dd, J ) 16.0, 2.4 Hz, 1H), 4.29 (dd, J ) 15.9,
2.4 Hz, 1H), 5.17 (ddt, J ) 10.4, 1.9, 1.3 Hz, 1H), 5.25 (dq, J
) 17.2, 1.6 Hz, 1H), 5.87 (ddt, J ) 17.2, 10.4, 5. 6 Hz, 1H),
7.22-7.28 (several peaks, 3H), 7.53 (m, 2H). 13C NMR δ 28.8,
57.3, 71.1, 72.3, 74.4, 77.1, 79.8, 117.1, 126.9, 129.0, 130.3,
132.5, 134.5.
3-P h en oxy-2-(2-p r op yn yloxy)p r op yl p h en yl selen id e
(4o): 1H NMR δ 2.39 (dt, J ) 3.0, 2.4 Hz, 1H), 3.20 (dd, J )
12.2, 6.0 Hz, 1H), 3.24 (dd, J ) 12.8, 6.0 Hz, 1H), 4.08-4.17
(several peaks, 3H), 4.23 (dd, J ) 2.4, 0.6 Hz, 1H), 4.37 (dd, J
) 2.4, 0.6 Hz, 1H), 6.84-6.98 (several peaks, 3H), 7.20-7.29
(several peaks, 5H), 7.53 (m, 2H). 13C NMR δ 28.8, 57.6, 68.8,
74.7, 76.6, 79.6, 114.5, 121.0, 121.1, 127.0, 129.1, 129.4, 132.6,
158.4.
3-(Ben zyloxy)-2-(2-pr opyn yloxy)pr opyl ph en yl selen ide
(4p ): 1H NMR δ 2.37 (t, J ) 2.4 Hz, 1H), 3.12 (dd, J ) 12.7,
5.9 Hz, 1H), 3.15 (dd, J ) 12.6, 6.4 Hz, 1H), 3.65 (d, J ) 4.8
Hz, 2H), 3.93 (tt, J ) 12.2, 4.7 Hz, 1H), 4.23 (dd, J ) 15.9, 2.4
Hz, 1H), 4.28 (dd, J ) 15.8, 2.3 Hz, 1H), 4.49 (s, 2H), 7.21-
7.36 (several peaks, 8H), 7.51 (m, 2H). 13C NMR δ 28.9, 57.3,
71.2, 73.4, 74.5, 77.2, 79.8, 126.9, 127.6, 128.3, 129.0, 130.3,
132.5, 138.0.
1-P h en yl-2-(2-p r op yn yloxy)et h yl p h en yl selen id e
(2d ): 1H NMR δ 2.39 (t, J ) 2.4 Hz, 1H), 3.96 (dd, J ) 10.0,
5.9 Hz, 1H), 4.10 (dd, J ) 10.0, 8.6 Hz, 1H), 4.11 (d, J ) 2.4
Hz, 2H), 4.49 (dd, J ) 8.5, 5.9 Hz, 1H), 7.19-7.29 (several
peaks, 8H), 7.45 (m, 2H). 13C NMR δ 46.8, 58.1, 72.3, 74.7,
79.3, 127.3, 127.9, 128.4, 128.8, 135.3, 139.5.
Typ ica l P r oced u r e for Gr ou p Tr a n sfer Ra d ica l Cy-
cliza tion . P r ep a r a tion of cis-3-[[[4-(Tr iflu or om eth yl)-
p h en yl]tellu r o]m eth yl]octa h yd r oben zofu r a n (6j). To a
solution of 2-(allyloxy)cyclohexyl 4-(trifluoromethyl)phenyl tel-
luride (0.46 g, 1.1 mmol) in dry benzene (10 mL) under
nitrogen was added hexabutylditin (0.026 g, 0.45 mmol), and
the resulting reaction mixture was irradiated with a sun lamp.
The position of the sun lamp was adjusted so that a vigorous
reflux could be maintained. After 1 h, TLC showed complete
consumption of the starting material. The flask was cooled
and the solvent removed in vacuo. The residue on purification
by flash chromatography (4%ether/pentane) afforded 0.31
g(69%) of the title compound as a 2:1 mixture of exo and endo
isomers. 1H NMR exo-6j δ 1.10-1.99 (several peaks, 9H), 2.29
(m, 1H), 2.91 (dd, J ) 11.8, 8.4 Hz, 1H), 3.11 (dd, J ) 11.9,
7.2 Hz, 1H), 3.47 (dd, J ) 9.1, 4.9 Hz, 1H), 4.01 (t, J ) 8.3 Hz,
3-[(P h en yltellu r o)m eth yl]cyclop en ta n ol (5a ): 1H NMR
trans-5a δ 1.23 (m, 1H), 1.43 (ddd, J ) 13.7, 9.8, 5.9 Hz, 1H),
1.59 (m, 1H), 1.86 (m, 1H), 1.96-2.08 (several peaks, 2H), 2.46-
2.59 (several peaks, 2H), 2.98 (d, J ) 7.2 Hz, 2H), 4.37 (m,
1H), 7.15-7.32 (several peaks, 3H), 7.73 (m, 2H). 1H NMR
cis-5a δ 1.27 (m, 1H), 1.47 (m, 1H), 1.67 (m, 1H), 1.74-1.90
(several peaks, 2H), 2.13-2.40 (several peaks, 3H), 3.04-3.07
(several peaks, 2H), 4.30 (m, 1H), 7.15-7.32 (several peaks,
3H), 7.73 (m, 2H). 13C NMR cis+trans δ 16.1, 16.7, 32.2, 32.4,
35.4, 35.7, 39.0, 40.0, 44.0, 44.4, 73.7, 73.8, 111.8, 127.5, 129.1,
138.3. MS m/ z (relative intensity) 303 (M+, 42.9).
3-[[[4-(N,N-d im e t h yla m in o)p h e n yl]t e llu r o]m e t h yl]-
1
cyclop en ta n ol (5b): H NMR trans-5b δ 1.21 (m, 1H), 1.43
(ddd, J ) 13.6, 9.4, 5.9 Hz, 1H), 1.57 (m, 1H), 1.84 (m, 1H),
1.94-2.07 (several peaks, 2H), 2.41-2.54 (several peaks, 2H),
2.85 (d, J ) 7.2 Hz, 2H), 2.95 (s, 6H), 4.38 (m, 1H), 6.56 (m,
2H), 7.63 (m, 2H). 1H NMR cis-5b δ 1.25 (m, 1H), 1.46 (m,
1H), 1.67 (m, 1H), 1.74-1.89 (several peaks, 2H), 2.13-2.25
(several peaks, 3H), 2.93 (dd, J ) 6.8, 2.8 Hz, 2H), 2.95 (s,
6H), 4.30 (m, 1H), 6.56 (m, 2H), 7.63 (m, 2H). 13C NMR
cis+trans δ 16.4, 17.0, 32.1, 32.3, 35.4, 35.7, 39.0, 39.9, 40.2,
44.0, 44.3, 73.8, 73.8, 94.9, 113.4, 141.0, 141.0, 150.2. MS m/ z
(relative intensity) 349 (M+, 46.9).
3-[[[4-(T r i flu o r o m e t h y l)p h e n y l]t e llu r o ]m e t h y l]-
cyclop en ta n ol (5c) 1H NMR trans-5c δ 1.24 (m, 1H), 1.43
(ddd, J ) 13.4, 10.1, 5.6 Hz, 1H), 1.61 (m, 1H), 1.88 (m, 1H),
1.98-2.10 (several peaks, 2H), 2.49-2.61 (several peaks, 2H),
3.03 (d, J ) 7.2 Hz, 2H), 4.40 (m, 1H), 7.41 (m, 2H), 7.77 (m,
2H). 1H NMR cis-5c δ 1.29 (m, 1H), 1.49 (m, 1H), 1.69 (m,
1H), 1.76-1.92 (several peaks, 2H), 2.16-2.29 (several peaks,
3H), 3.10 (dd, J ) 11.6, 7.0 Hz, 1H), 3.13 (dd, J ) 11.6, 7.0
Hz, 1H), 4.34 (m, 1H), 7.41 (m, 2H), 7.77 (m, 2H). 13C NMR
cis+trans δ 16.4, 17.1, 32.3, 32.5, 35.4, 35.8, 38.9, 39.9, 44.0,
44.4, 73.6, 73.7, 117.6, 122.8, 125.55, 125.59, 129.3, 129.6,
137.4. MS m/ z (relative intensity) 374 (M+, 4.8).
3-[(2-Th ien yltellu r o)m eth yl]cyclopen tan ol (5d): 1H NMR
trans-5d δ 1.20 (m, 1H), 1.42 (ddd, J ) 13.4, 9.5, 5.6 Hz, 1H),
1.59 (m, 1H), 1.86 (m, 1H), 1.96-2.08 (several peaks, 2H), 2.48
(m, 2H), 2.87 (d, J ) 7.2 Hz, 2H), 4.38 (m, 1H), 6.92 (dd, J )
5.2, 3.4 Hz, 1H), 7.37 (dd, J ) 3.4, 1.2 Hz, 1H), 7.42 (dd, J )
5.2, 1.1 Hz, 1H). 1H NMR cis-5d δ 1.26 (m, 1H), 1.46 (m, 1H),
1.68 (m, 1H), 1.75-1.91 (several peaks, 2H), 2.13-2.25 (several
peaks, 3H), 2.95 (dd, J ) 7.0, 1.2 Hz, 1H), 4.32 (m, 1H), 6.92
(dd, J ) 5.2, 3.5 Hz, 1H), 7.37 (dd, J ) 3.4, 1.2 Hz, 1H), 7.42
(dd, J ) 5.2, 1.1 Hz, 1H). 13C NMR cis+trans δ 19.0, 19.6,
32.0, 32.2, 35.3, 35.7, 38.8, 39.7, 43.8, 44.2, 73.6, 73.7, 97.4,
128.8, 134.0, 141.1. MS m/ z (relative intensity) 312 (M+, 8.3).
2-(3-Bu t e n yl)-4-[(2-t h ie n ylt e llu r o)m e t h yl]t e t r a h y-
d r ofu r a n (6d ): 1H NMR trans-6d δ 1.45-1.72 (several peaks,
2H), 1.72-1.77 (several peaks, 2H), 2.01-2.19 (several peaks,
2H), 2.55 (m, 1H), 2.81 (dd, J ) 11.8, 7.6 Hz, 1H), 2.87 (dd, J
) 11.7, 7.4 Hz, 1H), 3.37 (dd, J ) 8.8, 6.7 Hz, 1H), 3.96 (dd, J
) 7.1, 5.8 Hz, 1H), 4.02 (dd, J ) 8.8, 6.7 Hz, 1H), 4.95 (ddt, J
) 10.2, 2.0, 1.2 Hz, 1H), 5.02 (dm, J ) 17.1 Hz, 1H), 5.81 (ddt,
J ) 17.0, 10.4, 6.7 Hz, 1H), 6.94 (dd, J ) 5.1, 3.4 Hz, 1H),
7.38 (dd, J ) 3.4, 1.1 Hz, 1H), 7.44 (dd, J ) 5.2, 1.1 Hz, 1H).
Cis-6d could not be resolved. 13C NMR cis+trans δ 15.0, 15.3,
30.3, 30.4, 35.1, 39.6, 40.3, 40.7, 41.1, 73.8, 74.2, 78.2, 79.6,
96.9, 114.6, 128.9, 134.4, 138.2, 141.5. MS m/ z (relative
intensity) 352 (M+, 10.6).
2-Eth yl-4-[[[4-(tr iflu or om eth yl)ph en yl]tellu r o]m eth yl]-
1
tetr a h yd r ofu r a n (6e): H NMR trans-6e δ 0.90 (t, J ) 7.5

170 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
Hz, 3H), 1.36-1.65 (several peaks, 2H), 1.75 (t, J ) 7.0 Hz,
2H), 2.58 (m, 1H), 2.98 (dd, J ) 11.8, 7.6 Hz, 1H), 3.06 (dd, J
) 11.9, 7.4 Hz, 1H), 3.40 (dd, J ) 8.7, 6.5 Hz, 1H), 3.91 (m,
1H), 4.02 (dd, J ) 8.8, 6.6 Hz, 1H), 7.42 (m, 2H), 7.79 (m, 2H).
1H NMR cis-6e δ 0.91 (t, J ) 7.5 Hz, 3H), 1.21 (dd, J ) 12.3,
9.0 Hz, 1H), 1.36-1.65 (several peaks, 2H), 2.23 (ddd, J ) 12.3,
7.5, 5.9 Hz, 1H), 2.61 (m, 1H), 3.00 (dd, J ) 11.4, 7.4 Hz, 1H),
3.05 (dd, J ) 11.7, 7.5 Hz, 1H), 3.53 (dd, J ) 8.6, 6.6 Hz, 1H),
3.80 (m, 1H), 3.89 (dd, J ) 8.6, 6.7 Hz, 1H), 7.42 (m, 2H), 7.79
(m, 2H). 13C NMR δ cis+trans 10.3, 10.4, 12.8, 13.2, 28.7, 39.4,
40.5, 41.1, 74.0, 74.3, 80.3, 81.7, 116.9, 125.7 (q), 129.7, 137.8.
MS m/ z (relative intensity) 388 (M+, 17.1).
2-P h en yl-4-[[[4-(tr iflu or om eth yl)ph en yl]tellu r o]m eth yl]-
tetr a h yd r ofu r a n (6f): 1H NMR trans-6f δ 2.00-2.06 (m, 2H),
2.63 (m, 1H), 2.97 (dd, J ) 12.0, 7.7 Hz, 1H), 3.04 (dd, J )
12.0, 7.3 Hz, 1H), 3.54 (dd, J ) 8.7, 6.6 Hz, 1H), 4.18 (dd, J )
8.7, 6.8 Hz, 1H), 4.99 (t, J ) 7.0 Hz, 1H), 7.14-7.29 (several
peaks, 5H), 7.36 (m, 2H), 7.73 (m, 2H). 1H NMR cis-6f δ 1.97-
2.09 (several peaks, 2H), 2.49 (ddd, J ) 12.2, 7.4, 6.2 Hz, 1H),
2.97 (m, 2H), 3.67 (dd, J ) 8.5, 7.1 Hz, 1H), 4.04 (dd, J ) 8.5,
7.3 Hz, 1H), 4.85 (dd, J ) 9.4, 6.1 Hz, 1H), 7.14-7.29 (several
peaks, 5H), 7.36 (m, 2H), 7.73 (m, 2H). 13C NMR cis+trans δ
12.2, 23.0, 40.6, 42.8, 75.1, 80.1, 125.4, 125.7, 127.2, 128.3,
137.9, 143.1. MS m/ z (relative intensity) 436 (M+, 6.2).
2-[(Allyloxy)m et h yl]-4-[[[4-(t r iflu or om et h yl)p h en yl]-
tellu r o]m eth yl]tetr a h yd r ofu r a n (6g): 1H NMR trans-6g δ
1.75 (ddd, J ) 12.7, 7.7, 5.9 Hz, 1H), 1.94 (ddd, J ) 12.7, 8.2,
6.5 Hz, 1H), 2.62 (m, 1H), 2.97 (dd, J ) 11.8, 7.6 Hz, 1H), 3.05
(dd, J ) 11.9, 7.3 Hz, 1H), 3.41 (d, J ) 5.2 Hz, 2H), 3.46 (dd,
J ) 8.7, 6.5 Hz, 1H), 4.00 (ddd, J ) 1.5, 1.3, 0.8 Hz, 1H), 4.01
(m, 2H), 4.24 (m, 1H), 5.16 (ddt, J ) 10.4, 1.8, 1.3 Hz, 1H),
5.25 (dq, J ) 17.2, 1.7 Hz, 1H), 5.89 (ddt, J ) 17.2, 10.4, 5.6
Hz, 1H), 7.45 (m, 2H), 7.81 (m, 2H). 13C NMR trans-6g δ 12.2,
36.5, 40.5, 72.4, 72.6, 74.7, 77.6, 117.0, 125.7 (q), 134.6, 137.9.
MS m/ z (relative intensity) 430 (M+, 10.1).
2-(P h en oxym eth yl)-4-[[[4-(tr iflu or om eth yl)p h en yl]tel-
lu r o]m eth yl]tetr a h yd r ofu r a n (6h ): 1H NMR trans-6h δ
1.88 (ddd, J ) 12.8, 7.8, 6.3 Hz, 1H), 2.11 (ddd, J ) 12.7, 8.1,
6.0 Hz, 1H), 2.70 (m, 1H), 3.03 (dd, J ) 11.8, 7.6 Hz, 1H), 3.10
(dd, J ) 11.9, 7.3 Hz, 1H), 3.55 (dd, J ) 8.6, 6.6 Hz, 1H), 3.93
(dd, J ) 9.8, 4.7 Hz, 1H), 3.97 (dd, J ) 9.6, 5.2 Hz, 1H), 4.12
(dd, J ) 8.7, 6.5 Hz, 1H), 4.45 (m, 1H), 6.86-6.97 (several
peaks, 3H), 7.26 (m, 2H), 7.43 (m, 2H), 7.80 (m, 2H). 1H NMR
cis-6h δ 1.58 (dt, J ) 12.5, 8.5 Hz, 1H), 2.35 (ddd, J ) 12.3,
7.6, 6.9 Hz, 1H), 2.68 (m, 1H), 3.03 (dd, J ) 11.8, 7.4 Hz, 1H),
3.13 (dd, J ) 11.9, 7.4 Hz, 1H), 3.55 (dd, J ) 8.4, 6.7 Hz, 1H),
3.64 (dd, J ) 8.6, 7.0 Hz, 1H), 4.02 (m, 2H), 4.34 (m, 1H), 6.86-
6.97 (several peaks, 3H), 7.26 (m, 2H), 7.43 (m, 2H), 7.80 (m,
2H). 13C NMR trans+cis- δ 11.9, 12.2, 36.6, 37.0, 40.5, 41.1,
70.1, 74.6, 74.8, 76.9, 77.9, 114.5, 114.5, 116.8, 120.9, 125.7
(q), 129.4, 129.7, 137.8, 137.9, 158.7. MS m/ z (relative
intensity) 466 (M+, 14.0).
27.4, 28.2, 28.6, 41.4, 45.2, 45.5, 45.6, 71.8, 73.8, 76.2, 78.3,
96.8, 96.8, 128.9, 128.9, 134.4, 134.5, 141.6, 141.7. MS m/ z
(relative intensity) 352 (M+, 35.9).
2-(3-Bu ten yl)-4-[[[4-(tr iflu or om eth yl)p h en yl]tellu r o]-
m eth ylen e]tetr a h yd r ofu r a n (7c): 1H NMR (Z)-7c δ 1.61 (m,
1H), 1.78 (m, 1H), 2.07-2.25 (several peaks, 2H), 2.45 (ddddd,
J ) 16.0, 8.8, 2.3, 2.3, 1.0 Hz, 1H), 2.85 (ddq, J ) 15.9, 5.8,
1.6 Hz, 1H), 4.04 (ddt, J ) 8.6, 7.1, 5.7 Hz, 1H), 4.20 (dddd, J
) 14.3, 2.5, 2.5, 1.0 Hz, 1H), 4.37 (dm, J ) 14.3 Hz, 1H), 4.98
(dm, J ) 10.2 Hz, 1H), 5.05 (dddd, J ) 17.1, 3.6, 1.6.0.4 Hz,
1H), 5.83 (ddt, J ) 17.0, 10.2, 6.6 Hz, 1H), 6.67 (m, 1H), 7.44
(m, 2H), 7.70 (m, 2H). 1H NMR (E)-7c δ 1.63 (m, 1H), 1.77
(m, 1H), 2.09-2.24 (several peaks, 3H), 2.65 (dm, J ) 16.2
Hz, 1H), 4.03 (m, 1H), 4.39 (dddd, J ) 13.4, 2.2, 2.2, 1.1 Hz,
1H), 4.53 (dm, J ) 13.5 Hz, 1H), 4.98 (ddt, J ) 10.2, 1.9, 1.3
Hz, 1H), 5.04 (dq, J ) 17.0, 1.6 Hz, 1H), 5.83 (ddt, J ) 17.1,
10.3, 6.5 Hz, 1H), 6.60 (m, 1H), 7.44 (m, 2H), 7.70 (m, 2H).
MS m/ z (relative intensity) 412 (M+, 100).
2-E t h y l-4-[[[4-(t r iflu o r o m e t h y l)p h e n y l]t e llu r o ]m -
1
eth ylen e]tetr a h yd r ofu r a n (7e): H NMR (E)-7e δ 0.88 (t,
J ) 7.4 Hz, 3H), 1.50-1.75 (several peaks, 2H), 2.19 (ddm, J
) 16.5, 8.6 Hz, 1H), 2.64 (ddm, J ) 16.5, 6.2 Hz, 1H), 3.95 (m,
1H), 4.39 (dddd, J ) 13.5, 2.2, 2.2, 1.2 Hz, 1H), 4.53 (m, 1H),
6.60 (m, 1H), 7.43 (m, 2H), 7.68 (m, 2H). 13C NMR (E)-7e δ
10.1, 30.3, 41.7, 72.0, 81.0, 89.1, 125.8, 125.9, 135.9, 155.3. 1H
NMR (Z)-7e δ 0.96 (t, J ) 7.4 Hz, 3H), 1.55 (dq, J ) 13.7, 7.3
Hz, 1H), 1.69 (dq, J ) 13.6, 7.5 Hz, 1H), 2.44 (ddddd, J ) 15.8,
8.7, 2.2, 2.2, 1.0 Hz, 1H), 2.83 (ddddd, J ) 15.7, 5.8, 1.7, 1.7,
1.1 Hz, 1H), 3.97 (dq, J ) 8.5, 6.1 Hz, 1H), 4.20 (dddd, J )
14.3, 2.5, 2.5, 1.0 Hz, 1H), 4.38 (ddddd, J ) 14.3, 3.9, 2.3, 1.0,
0.5 Hz, 1H), 6.67 (ddd, J ) 4.7, 2.3, 1.6 Hz, 1H), 7.43 (m, 2H),
7.68 (m, 2H). 13C NMR (Z)-7e δ 10.1, 28.0, 41.1, 73.9, 82.0,
87.9, 125.8, 125.9, 135.9, 156.0. MS m/ z (relative intensity)
386 (M+, 19.1).
2-P h e n yl-4-[[[4-(t r iflu or om e t h yl)p h e n yl]t e llu r o]m -
eth ylen e]tetr a h yd r ofu r a n (7f): 1H NMR (E)-7f δ 2.57
(ddddd, J ) 16.3, 8.5, 2.8, 2.3, 0.9 Hz, 1H), 2.99 (ddddd, J )
16.3, 6.5, 2.1, 2.1, 1.2 Hz, 1H), 4.57 (dddd, J ) 13.4, 2.1, 2.1,
1.2 Hz, 1H), 4.72 (ddddd, J ) 13.5, 2.5, 0.8, 0.8, 0.5 Hz, 1H),
5.07 (dd, J ) 8.5, 6.5 Hz, 1H), 6.68 (ddt, J ) 4.6, 2.7, 2.0 Hz,
1H), 7.26-7.37 (several peaks, 5H), 7.44 (m, 2H), 7.70 (m, 2H).
13C NMR (E)-7f δ 44.4, 72.4, 77.2, 80.7, 89.6, 125.9 (q), 127.8,
128.5, 136.0, 136.1, 141.1, 154.3. 1H NMR (Z)-7f δ 2.81 (ddddd,
J ) 15.8, 8.8, 2.2, 2.2, 1.0 Hz, 1H), 3.16 (ddddd, J ) 15.9, 6.2,
1.7, 1.7, 1.0 Hz, 1H), 4.38 (dddd, J ) 14.2, 4.7, 2.3, 1.0 Hz,
1H), 4.57 (dddd, J ) 14.3, 2.7, 1.5, 0.9 Hz, 1H), 5.08 (dd, J )
8.7, 6.0 Hz, 1H), 6.75 (ddd, J ) 4.7, 2.3, 1.5 Hz, 1H), 7.27-
7.38 (several peaks, 5H), 7.44 (m, 2H), 7.70 (m, 2H). 13C NMR
(Z)-7f δ 43.8, 74.3, 77.2, 81.7, 88.7, 125.8 (q), 127.8, 128.5,
129.8, 136.0, 141.1, 155.1. MS m/ z (relative intensity) 434
(M+, 7.0).
2-[(Allyloxy)m et h yl]-4-[[[4-(t r iflu or om et h yl)p h en yl]-
tellu r o]m eth ylen e]tetr a h yd r ofu r a n (7g): 1H NMR (E)-7g
δ 2.40 (ddddd, J ) 16.5, 7.9, 2.8, 2.2, 0.8 Hz, 1H), 2.63 (ddddd,
J ) 16.5, 6.8, 2.2, 1.7, 1.1 Hz, 1H), 3.52 (dd, J ) 10.1, 5.8 Hz,
1H), 3.56 (dd, J ) 10.3, 4.2 Hz, 1H), 4.02-4.05 (several peaks,
2H), 4.27 (m, 1H), 4.44 (dddd, J ) 13.4, 2.1, 2.1, 1.1 Hz, 1H),
4.58 (dm, J ) 13.4 Hz, 1H), 5.19 (ddt, J ) 10.4, 1.7, 1.2 Hz,
1H), 5.27 (dq, J ) 17.2, 1.6 Hz, 1H), 5.91 (ddt, J ) 17.2, 10.3,
5.6 Hz, 1H), 6.63 (m, 1H), 7.43 (m, 2H), 7.71 (m, 2H). 13C NMR
(E)-7g δ 38.5, 71.8, 72.4, 72.5, 78.3, 89.6, 117.3, 119.9, 125.8
(q), 134.5, 136.0, 154.4. 1H NMR (Z)-7g δ 2.66 (ddddd, J )
16.0, 8.1, 2.2, 2.2, 1.0 Hz, 1H), 2.83 (ddm, J ) 16.0, 6.4, Hz,
1H), 3.52 (dd, J ) 10.4, 5.4 Hz, 1H), 3.54 (dd, J ) 10.3, 4.6
Hz, 1H), 4.04 (m, 2H), 4.26 (dddd, J ) 14.2, 2.4, 2.2, 1.0 Hz,
1H), 4.29 (m, 1H), 4.42 (dm, J ) 14.2 Hz, 1H), 5.19 (ddt, J )
10.4, 1.8, 1.2 Hz, 1H), 5.28 (dq, J ) 17.2, 1.7 Hz, 1H), 5.91
(ddd, J ) 17.2, 10.3, 5.6 Hz, 1H), 6.70 (ddd, J ) 4.6, 2.4, 1.7
Hz, 1H), 7.43 (m, 2H), 7.69 (m, 2H). 13C NMR (Z)-7g δ 37.8,
71.8, 72.5, 74.3, 79.2, 88.5, 108.9, 117.3, 119.9, 125.8 (q), 129.7,
134.5, 135.9, 154.9. MS m/ z (relative intensity) 428 (M+, 18.0).
2-(P h en oxym eth yl)-4-[[[4-(tr iflu or om eth yl)p h en yl]tel-
2-[(Ben zyloxy)m eth yl]-4-[[[4-(tr iflu or om eth yl)p h en yl]-
tellu r o]m eth yl]tetr a h yd r ofu r a n (6i): H NMR trans-6i δ
1
1.74 (ddd, J ) 12.6, 7.8, 5.9 Hz, 1H), 1.95 (ddd, J ) 12.6, 8.0,
6.4 Hz, 1H), 2.55-2.66 (m, 1H), 2.97 (dd, J ) 11.9, 7.6 Hz,
1H), 3.04 (dd, J ) 11.9, 7.2 Hz, 1H), 3.44 (s, 1H), 3.45 (s, 1H),
3.47 (dd, J ) 8.6, 6.6 Hz, 1H), 4.05 (dd, J ) 8.7, 6.5 Hz, 1H),
4.21-4.28 (m, 1H), 4.53 (d, J ) 12.1 Hz, 1H), 4.57 (d, J ) 12.1
Hz, 1H), 7.27-7.35 (m, 5H), 7.40-7.45 (m, 2H), 7.76-7.82 (m,
2H). 13C NMR trans-6i δ 12.3, 36.6, 40.5, 72.6, 73.4, 74.7, 77.7,
125.7 (q), 127.5 (q), 128.3, 137.8, 138.2. MS m/ z (relative
intensity) 480 (M+, 2.3).
ci s-3-[(2-T h ie n y lt e llu r o )m e t h y l]o c t a h y d r o b e n zo -
fu r a n (6k ): 1H NMR exo-6k δ 1.05-1.65 (several peaks, 7H),
1.77-1.84 (several peaks, 2H), 2.24 (m, 1H), 2.75 (dd, J ) 11.8,
8.2 Hz, 1H), 2.93 (dd, J ) 11.8, 7.4 Hz, 1H), 3.45 (dd, J ) 9.1,
4.9 Hz, 1H), 3.95 (m, 1H), 4.16 (dd, J ) 9.1, 7.5 Hz, 1H), 6.94
(dd, J ) 5.2, 3.4 Hz, 1H), 7.38 (dd, J ) 3.4, 1.1 Hz, 1H), 7.44
(dd, J ) 5.2, 1.1 Hz, 1H). 1H NMR endo-6k δ 1.06 (m, 1H),
1.38-1.54 (several peaks, 5H), 1.71 (m, 1H), 1.90-1.98 (several
peaks, 2H), 2.68 (m, 1H), 2.73 (dd, J ) 11.4, 7.3 Hz, 1H), 2.81
(dd, J ) 11.4, 8.1 Hz, 1H), 3.50 (dd, J ) 9.5, 8.1 Hz, 1H), 3.94
(m, 1H), 4.00 (t, J ) 8.4 Hz, 1H), 6.94 (dd, J ) 5.2, 3.4 Hz,
1H), 7.39 (dd, J ) 3.4, 1.1 Hz, 1H), 7.44 (dd, J ) 5.2, 1.1 Hz,
1H). 13C NMR exo+endo δ 8.3, 15.9, 20.3, 20.9, 21.6, 23.6, 24.2,
1
lu r o]m eth ylen e]tetr a h yd r ofu r a n (7h ): H NMR (E)-7h δ
2.54 (ddddd, J ) 16.6, 7.5, 2.9, 2.1, 0.9 Hz, 1H), 2.76 (ddddd,
J ) 16.5, 6.9, 2.3, 1.8, 1.1 Hz, 1H), 4.06 (d, J ) 4.9 Hz, 2H),
4.46-4.55 (several peaks, 2H), 4.64 (dm, J ) 13.4 Hz, 1H),

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 171
6.68 (tt, J ) 4.8, 2.4 Hz, 1H), 6.90-6.99 (m, 3H), 7.28 (m, 2H),
3-Meth ylcyclop en ta n ol (8) was compared with an au-
thentic sample. For the assignment of the cis and trans
isomers, the material was benzoylated by treatment with
benzoyl chloride and pyridine in diethyl ether and analyzed
by DEPT, INEPT, NOESY, PECOSY, HSQC, NOE difference,
and ZTOCSY experiments. 1H NMR trans-3-methylcyclopen-
tanol benzoate δ 1.05 (d, J ) 6.6 Hz, 3H), 1.18 (m, 1H), 1.49
(ddd, J ) 14.0, 9.8, 6.2 Hz, 1H), 1.76-1.85 (several peaks, 2H),
2.00 (m, 1H), 2.15-2.30 (several peaks, 2H), 5.43 (m, 1H),
1
7.44 (m, 2H), 7.72 (m, 2H). 13C NMR H NMR (E)-7h δ 38.5,
69.6, 72.5, 77.5, 90.0, 114.6, 121.1, 125.9 (q), 129.5, 136.2,
153.9, 158.6. 1H NMR (Z)-7h δ 2.79 (ddddd, J ) 16.0, 7.5,
2.1, 2.1, 1.0 Hz, 1H), 2.97 (ddddd, J ) 16.1, 6.7, 1.8, 1.8, 1.2
Hz, 1H), 4.02 (dd, J ) 9.9, 4.7 Hz, 1H), 4.07 (dd, J ) 9.9, 5.4
Hz, 1H), 4.33 (dddd, J ) 14.2, 2.4, 2.1, 1.0 Hz, 1H), 4.44-4.55
(several peaks, 2H), 6.75 (tt, J ) 4.4, 2.4 Hz, 1H), 6.89-6.99
(several peaks, 3H), 7.28 (m, 2H), 7.44 (m, 2H), 7.71 (m, 2H).
13C NMR (Z)-7h δ 37.9, 69.6, 74.4, 78.3, 89.0, 114.6, 121.1,
125.9 (q), 129.5, 136.1, 154.2, 158.6. MS m/ z (relative
intensity) 464 (M+, 13.9).
1
7.39-7.47 (several peaks, 2H), 7.54 (m, 1H), 8.03 (m, 2H). H
NMR cis-3-methylcyclopentanol benzoate δ 1.10 (d, J ) 6.6
Hz, 3H), 1.35-1.44 (several peaks, 2H), 1.80-2.10 (several
peaks, 4H), 3.32 (m, 1H), 5.37 (m, 1H), 7.39-7.47 (several
peaks, 2H), 7.54 (m, 1H), 8.03 (m, 2H). 13C NMR trans+cis δ
20.4, 21.0, 32.6, 32.6, 32.7, 32.7, 32.9, 33.0, 41.1, 41.6, 77.6,
77.8, 128.2, 129.4, 130.8, 132.6, 166.3, 166.3.
2-[(Ben zyloxy)m eth yl]-4-[[[4-(tr iflu or om eth yl)p h en yl]-
tellu r o]m eth ylen e]tetr a h yd r ofu r a n (7i): 1H NMR (E)-7i
δ 2.41 (ddt, J ) 16.6, 8.3, 2.5 Hz, 1H), 2.63 (ddddd, J ) 16.5,
6.9, 2.0, 1.6, 1.1 Hz, 1H), 3.55 (dd, J ) 10.3, 5.5 Hz, 1H), 3.58
(dd, J ) 10.2, 4.3 Hz, 1H), 4.30 (dddd, J ) 12.2, 7.7, 5.3, 4.2
Hz, 1H), 4.45 (dddd, J ) 13.3, 4.0, 2.0, 1.1 Hz, 1H), 4.55-4.62
(several peaks, 3H), 6.65 (m, 1H), 7.26-7.35 (several peaks,
5H), 7.42 (m, 2H), 7.70 (m, 2H). 13C NMR (E)-7i δ 38.5, 71.8,
72.4, 73.5, 78.3, 89.6, 125.8, 125.9, 127.7, 128.4, 136.1, 138.0,
154.4. 1H NMR (Z)-7i δ 2.67 (ddddd, J ) 16.0, 7.9, 2.2, 2.2,
1.0 Hz, 1H), 2.83 (ddddd, J ) 16.0, 6.5, 1.7, 1.7, 1.0 Hz, 1H),
3.55 (d, J ) 4.9 Hz, 2H), 4.20 (dm, J ) 14.2 Hz, 1H) 4.27 (dddd,
J ) 14.2, 2.4, 2.2, 1.0 Hz, 1H), 4.31 (ddt, J ) 7.9, 6.5, 4.9 Hz,
1H), 4.57 (d, J ) 12.2 Hz, 1H), 4.60 (d, J ) 12.1 Hz, 1H), 6.71
(m, 1H), 7.26-7.35 (several peaks, 5H), 7.42 (m, 2H), 7.67 (m,
2H). 13C NMR (Z)-7i δ 37.8, 71.8, 73.5, 74.3, 79.2, 88.4, 125.8,
125.9, 127.7, 128.4, 135.9, 138.0, 154.9. MS m/ z (relative
intensity) 478 (M+, 1.3).
2-(3-Bu t en yl)-4-m et h ylt et r a h yd r ofu r a n (9l): 1H NMR
trans-9l δ 1.02 (d, J ) 6.8 Hz, 3H), 1.55-1.72 (several peaks,
6H), 2.31 (m, 1H), 3.25 (dd, J ) 8.4, 6.9 Hz, 1H), 3.94 (m, 1H),
3.98 (dd, 8.4, 6.8 Hz, 1H), 4.94 (ddt, J ) 10.2, 2.0, 1.3 Hz, 1H),
5.02 (ddt, J ) 17.1, 2.0, 1.6 Hz, 1H), 5.83 (ddt, J ) 17.0, 10.0,
6.5 Hz, 1H). 1H NMR cis-9l δ 1.03 (d, J ) 6.7 Hz, 3H), 1.09
(dd, J ) 11.8, 9.5 Hz, 1H), 2.10-2.18 (several peaks, 5H), 2.31
(m, 1H), 3.34 (t, J ) 8.0 Hz, 1H), 3.87 (m, 2H), 4.94 (ddt, J )
10.2, 2.0, 1.3 Hz, 1H), 5.02 (ddt, J ) 17.1, 2.0, 1.6 Hz, 1H),
5.83 (ddt, J ) 17.0, 10.0, 6.5 Hz, 1H). 13C NMR cis+trans δ
17.9, 18.1, 30.5, 30.6, 33.2, 34.4, 35.3, 39.6, 40.8, 74.4, 74.8,
78.2, 79.6, 114.4, 138.5. MS m/ z (relative intensity) 140 (M+,
0.8).
4-Meth yl-2-ph en yltetr ah ydr ofu r an (9m ): 1H NMR trans-
9m δ 1.09 (d, J ) 6.9 Hz, 3H), 1.91-2.04 (several peaks, 2H),
2.42 (m, 1H), 4.47 (dd, J ) 8.2, 7.0 Hz, 1H), 4.21 (dd, J ) 8.3,
6.5 Hz, 1H), 5.02 (dd, J ) 7.3, 6.6 Hz, 1H), 7.21-7.35 (several
peaks, 5H). 13C NMR trans-9m δ 17.7, 34.9, 42.6, 75.6, 80.0,
125.4, 126.9, 128.2, 143.9. 1H NMR cis-9m δ 1.09 (d, J ) 5.0
Hz, 1H), 1.44 (dd, J ) 10.1, 2.4 Hz, 1H), 2.43-2.54 (several
peaks, 2H), 3.57 (t, J ) 8.0 Hz, 1H), 4.08 (t, J ) 8.1 Hz, 1H),
4.91 (dd, J ) 9.7, 5.6 Hz, 1H), 7.21-7.35 (several peaks, 5H).
13C NMR cis-9m δ 17.3, 33.2, 43.9, 75.4, 81.5, 125.5, 127.1,
128.2, 143.4. Rawal and co-workers7 have published NMR
data for the mixture of cis and trans isomers and Watanabe15
and Tada16 have described their synthesis.
cis-3-[[[4-(Tr iflu or om eth yl)p h en yl]tellu r o]m eth ylen e]-
octa h yd r oben zofu r a n (7j): 1H NMR (E)-7j δ 1.17-1.33
(several peaks, 2H), 1.45-1.77 (several peaks, 5H), 2.06 (m,
1H), 2.58 (m, 1H), 3.98 (m, 1H), 4.43 (ddd, J ) 14.0, 1.9, 0.7
Hz, 1H), 4.67 (dddd, J ) 14.0, 1.9, 1.3, 0.5 Hz, 1H), 6.46 (ddd,
J ) 1.9, 1.9, 1.1 Hz, 1H), 7.43 (m, 2H), 7.68 (m, 2H). 13C NMR
(E)-7j δ 20.1, 24.1, 26.6, 27.6, 47.1, 71.1, 79.0, 86.7, 109.5, 125.8
(q), 135.6. 1H NMR (Z)-7j δ 1.22-1.83 (several peaks, 8H),
2.74 (m, 1H), 4.10 (q, J ) 4.7 Hz, 1H), 4.26 (ddd, J ) 14.5, 2.6,
0.9 Hz, 1H), 4.42 (dm, J ) 14.6 Hz, 1H), 6.61 (ddd, J ) 2.5,
2.5, 1.4 Hz, 1H), 7.43 (m, 2H), 7.68 (m, 2H). 13C NMR (Z)-7j
δ 21.0, 23.2, 27.3, 27.8, 46.5, 73.1, 78.5, 86.8, 112.7, 125.8 (q),
135.6, 160.5. MS m/ z (relative intensity) 412 (M+, 100).
2-P h en yl-4-isop r op yltetr a h yd r ofu r a n (9m ′): 1H NMR
trans-9m ′ δ 0.90 (d, J ) 7.2 Hz, 3H), 0.92 (d, J ) 7.2 Hz, 3H),
1.60 (m, 1H), 1.97-2.06 (several peaks, 3H), 3.55 (m, 1H), 4.23
(m, 1H), 5.02 (m, 1H), 7.22-7.37 (several peaks, 5H). 1H NMR
cis-9m ′ δ 0.91 (d, J ) 6.7 Hz, 3H), 0.94 (d, J ) 6.7 Hz, 3H),
1.40-1.57 (several peaks, 2H), 2.15 (m, 1H), 2.41 (tt, J ) 13.0,
5.7 Hz, 1H), 3.72 (t, J ) 8.4 Hz, 1H), 4.11 (t, J ) 8.2 Hz, 1H),
4.90 (dd, J ) 10.0, 5.5 Hz, 1H), 7.22-7.37 (several peaks, 5H).
13C NMR cis+trans δ 21.4, 21.5, 21.6, 21.6, 31.6, 32.0, 39.2,
40.8, 46.1, 48.2, 72.9, 73.1, 80.5, 81.7, 125.4, 125.6, 126.9, 127.1,
128.2, 128.3, 143.2, 144.2. Rawal and co-workers7 have
published NMR data for the mixture of cis and trans isomers.
2-[(Allyloxy)m eth yl]-4-m eth yltetr a h yd r ofu r a n (9n ): 1H
NMR trans-9n δ 1.02 (d, J ) 6.7 Hz, 1H), 1.56 (ddd, J ) 12.4,
7.7, 6.4 Hz, 1H), 1.83 (ddd, J ) 12.4, 8.1, 6.3 Hz, 1H), 2.31
(ddt, J ) 13.4, 8.2, 6.7 Hz, 1H), 3.30 (dd, J ) 8.3, 7.0 Hz, 1H),
3.41 (d, J ) 5.3 Hz, 2H), 3.92-4.02 (several peaks, 3H), 4.16
(ddt, J ) 7.7, 6.2, 5.3 Hz, 1H), 5.16 (ddt, J ) 10.3, 1.7, 1.3 Hz,
1H), 5.26 (dq, J ) 17.2, 1.6 Hz, 1H), 5.91 (ddt, J ) 17.2, 10.4,
5.6 Hz, 1H). 13C NMR trans-9n δ 17.7, 33.1, 36.4, 72.3, 73.0,
75.3, 77.4, 116.9, 134.8. MS m/ z (relative intensity) 157 (M+
+ 1, 0.8), 141 (M+ - CH3, 0.5), 125 (M+ - allyl, <0.5), 85 (M+
- CH2O - allyl, 100).
Typ ica l P r oced u r e for Red u ctive Ra d ica l Cycliza tion .
P r ep a r a tion of 2-[(Ben zyloxy)m eth yl]-4-m eth yltetr a h y-
d r ofu r a n (9p ). To a solution of 2-(allyloxy)-3-(benzyloxy)-
propyl phenyl selenide (0.52 g, 1.4 mmol) in dry benzene (20
mL) under nitrogen was added AIBN (0.067 g, 0.41 mmol).
The reaction flask was then lowered in an oil bath preheated
to 90 °C. Tributyltin hydride (0.52 g, 1.8 mmol) was then
added dropwise and the reaction mixture refluxed. After 45
min, TLC showed the complete consumption of the starting
material. The flask was cooled and the solvent removed in
vacuo. After purification by flash chromatography (20% ether/
pentane), 0.28 g (94%) of the title compound was obtained as
a 1:3 mixture of cis and trans isomers. 1H NMR trans-9p δ
1.02 (d, J ) 6.8 Hz, 3H), 1.56 (ddd, J ) 12.4, 6.7, 6.4 Hz, 1H),
1.84 (ddd, J ) 12.3, 8.1, 6.2 Hz, 1H), 2.32 (ddt, J ) 13.4, 8.1,
6.7 Hz, 1H), 3.31 (dd, J ) 8.3, 7.0 Hz, 1H), 3.45 (d, J ) 5.2 Hz,
2H), 4.00 (dd, J ) 8.2, 6.6 Hz, 1H), 4.20 (ddt, J ) 7.7, 6.3, 5.2
Hz, 1H), 4.54 (d, J ) 12.2 Hz, 1H), 4.59 (d, J ) 12.1 Hz, 1H),
7.24-7.35 (several peaks, 5H). 13C NMR trans-9p δ 17.7, 33.2,
36.4, 72.9, 73.3, 75.3, 77.5, 127.5, 127.6, 128.3, 138.4. 1H NMR
cis-9p δ 1.04 (d, J ) 6.6 Hz, 3H), 1.23 (dt, J ) 12.2, 9.1 Hz,
1H), 2.11 (dt, J ) 12.3, 6.7 Hz, 1H), 2.33 (m, 1H), 3.37 (t, J )
8.2 Hz, 1H), 3.50 (d, J ) 5.1 Hz, 2H), 3.92 (t, J ) 7.8 Hz, 1H),
4.13 (m, 1H), 4.56 (d, J ) 12.2 Hz, 1H), 4.61 (d, J ) 12.2 Hz,
1H), 7.24-7.35 (several peaks, 5H). 13C NMR cis-9p δ 17.3,
34.1, 37.1, 73.0, 73.2, 74.8, 78.7, 127.5, 127.6, 128.3, 138.4.
Anal. Calcd for C13H18O2: C, 75.69; H, 8.80. Found: C, 75.47;
H, 8.70. MS m/ z (relative intensity) 206 (M+, 6.9).
4-Meth yl-2-(p h en oxym eth yl)tetr a h yd r ofu r a n (9o): 1H
NMR trans-9o δ 1.06 (d, J ) 6.7 Hz, 3H), 1.68 (ddd, J ) 12.4,
7.8, 6.7 Hz, 1H), 1.98 (ddd, J ) 12.4, 7.9, 5.9 Hz, 1H), 2.39 (m,
1H), 3.37 (dd, J ) 8.3, 7.1 Hz, 1H), 3.91 (dd, J ) 9.6, 4.8 Hz,
1H), 3.96 (dd, J ) 9.6, 5.7 Hz, 1H), 4.04 (dd, J ) 8.3, 6.6 Hz,
1H), 4.38 (m,1H), 6.89-6.96 (several peaks, 3H), 7.27 (m, 2H).
13C NMR trans-9o δ 17.5, 33.2, 36.4, 70.4, 75.4, 76.7, 114.5,
120.7, 129.3, 158.8. 1H NMR cis-9o δ 1.08 (d, J ) 6.8 Hz, 3H),
1.36 (dd, J ) 12.1, 9.2 Hz, 1H), 2.24 (dt, J ) 12.4, 6.7 Hz, 1H),
2.39 (m, 1H), 3.42 (t, J ) 8.2 Hz, 1H), 3.95-4.01 (several peaks,
3H), 4.31 (m, 1H), 6.89-6.96 (several peaks, 3H), 7.26 (m, 2H).
The following compounds were similarly prepared. As
judged by 1H NMR spectroscopy, the purity of the materials
were >98%. For yields, cis/ trans- and syn/ anti-ratios, see
Table 2.

172 J . Org. Chem., Vol. 62, No. 1, 1997
Engman and Gupta
13C NMR cis-9o δ 17.2, 34.2, 37.2, 70.6, 75.0, 77.8, 114.5, 120.7,
129.3, 158.8. MS m/ z (relative intensity) 192 (M+, 11.0).
2-(P h en oxym eth yl)-4-isop r op yltetr a h yd r ofu r a n (9o′):
1H NMR trans-9o′ δ 0.89 (d, J ) 7.2 Hz, 3H), 0.95 (d, J ) 6.6
Hz, 3H), 1.51 (m, 1H), 1.76 (m, 1H), 1.91-2.06 (several peaks,
2H), 3.45 (t, J ) 8.4 Hz, 1H), 3.87 (dd, J ) 9.5, 5.1 Hz, 1H),
3.93 (dd, J ) 9.6, 5.9 Hz, 1H), 4.07 (m, 1H), 4.33 (m, 1H), 6.90-
6.96 (several peaks, 3H), 7.27 (m, 2H). 1H NMR cis-9o′ δ 0.90
(d, J ) 7.0 Hz, 3H), 0.96 (d, J ) 6.9 Hz, 3H), 1.40 (m, 1H),
1.53 (m, 1H), 2.04 (m, 1H), 2.18 (dddm, J ) 11.9, 7.3, 5.9 Hz,
1H), 3.54 (dd, J ) 9.0, 8.3 Hz, 1H), 3.97-4.05 (several peaks,
3H), 4.31 (m, 1H), 6.90-6.96 (several peaks, 3H), 7.27 (m, 2H).
13C NMR trans+cis δ 21.5, 21.5, 21.6, 21.6, 31.6, 31.9, 33.2,
34.1, 46.3, 47.6, 70.5, 70.6, 72.5, 73.0, 77.2, 77.9, 114.5, 114.5,
120.8, 129.3, 129.4, 158.9. MS m/ z (relative intensity) 220
(M+, 14.2).
2-[(Be n zyloxy)m e t h yl]-4-isop r op ylt e t r a h yd r ofu r a n
(9p ′): 1H NMR trans-9p ′ δ 0.87 (d, J ) 6.6 Hz, 3H), 0.92 (d, J
) 6.6 Hz, 3H), 1.46 (ddt, J ) 13.2, 8.9, 6.6 Hz, 1H), 1.64 (dt,
J ) 12.3, 8.2 Hz, 1H), 1.82 (m, 1H), 1.92 (m, 1H), 3.39 (t, J )
8.6 Hz, 1H), 3.42 (dd, J ) 9.9, 5.0 Hz, 1H), 3.45 (dd, J ) 9.8,
5.8 Hz, 1H), 4.03 (dd, J ) 8.5, 7.3 Hz, 1H), 4.15 (ddt, J ) 8.2,
5.8, 4.9 Hz, 1H), 4.55 (d, 12.1 Hz, 1H), 4.59 (d, J ) 12.0 Hz,
1H), 7.25-7.36 (several peaks, 5H). 13C NMR trans-9p ′ δ 21.4,
21.5, 31.6, 33.1, 46.3, 72.8, 73.0, 73.3, 77.9, 127.5, 127.7, 128.3,
138.3. 1H NMR cis-9p ′ δ 0.87 (d, J ) 6.6 Hz, 3H), 0.92 (d, J
) 6.6 Hz, 3H), 1.28 (m, 1H), 1.47 (m, 1H), 1.97 (m, 1H), 2.05
(m, 1H), 3.45-3.58 (several peaks, 3H), 3.95 (t, J ) 7.9 Hz,
1H), 4.09 (m, 1H), 4.55 (d, J ) 12.1 Hz, 1H), 4.59 (d, J ) 12.0
Hz, 1H), 7.25-7.36 (several peaks, 5H). 13C NMR cis-9p ′ δ
21.5, 21.6, 31.9, 34.0, 47.5, 72.3, 72.9, 72.9, 78.8, 127.4, 127.6,
128.2, 138.3. MS m/ z (relative intensity) 234 (M+, 5.3).
cis-3-Meth ylocta h yd r oben zofu r a n (9q): 1H NMR exo-9q
δ 0.98 (d, J ) 7.4 Hz, 3H), 1.18-1.82 (several peaks, 9H), 2.04
(m, 1H), 3.32 (dd, J ) 8.6, 5.6 Hz, 1H), 3.94 (m, 1H), 4.11 (t,
J ) 7.9 Hz, 1H). 1H NMR endo-9q δ 0.92 (d, J ) 7.3 Hz, 3H),
1.05-1.82 (several peaks, 8H), 1.95 (m, 1H), 2.41 (m, 1H), 3.44
(dd, J ) 10.2, 7.9 Hz, 1H), 3.86-3.98 (several peaks, 2H). 13C
NMR exo+endo δ 11.5, 18.3, 20.5, 21.5, 21.9, 23.2, 24.5, 26.7,
28.6, 28.7, 37.7, 38.0, 41.3, 45.2, 72.3, 73.9, 76.3, 78.3. MS
m/ z (relative intensity) 140 (M+, 50.8). This compound was
previously prepared by Tada16 and Torii.22
H, 1H), 4.96 (dt, J ) 4.6, 2.2 Hz, 1H), 5.03 (dt, J ) 4.4, 2.3 Hz,
1H), 6.90-6.97 (several peaks, 3H), 7.26 (m, 2H). 13C NMR δ
35.2, 69.7, 71.3, 77.6, 104.8, 114.5, 120.9, 129.4, 147.0, 158.7.
MS m/ z (relative intensity) 190 (M+, 14.2).
2-[(Ben zyloxy)m et h yl]-4-m et h ylen et et r a h yd r ofu r a n
1
(10p ): H NMR δ 2.38 (ddddd, J ) 15.7, 5.6, 3.5, 2.3, 1.0 Hz,
1H), 2.61 (ddddd, J ) 15.7, 6.6, 2.9, 2.0, 1.1 Hz, 1H), 3.51 (d,
J ) 14.4 Hz, 1H), 3.56 (d, J ) 14.4 Hz, 1H), 4.21 (ddt, J ) 8.0,
6.6, 5.2 Hz, 1H), 4.28 (dddd, J ) 13.1, 4.5, 2.1, 1.0 Hz, 1H),
4.42 (dm, J ) 13.1, Hz, 1H), 4.57 (d, J ) 12.0 Hz, 1H), 4.61 (d,
J ) 12.0 Hz, 1H), 4.92 (quint, J ) 2.3 Hz, 1H), 4.99 (quint, J
) 2.3 Hz, 1H), 7.26-7.37 (several peaks, 5H). 13C NMR δ 35.2,
71.2, 72.0, 73.4, 78.5, 104.4, 127.6, 127.7, 128.3, 138.2, 147.5.
MS m/ z (relative intensity) 203 (M+ - 1, 2.1), 126 (M+ - C6H5,
3.0), 91 (C6H5CH2+, 100).
cis-3-Meth ylen eocta h yd r oben zofu r a n (10q): 1H NMR
δ 1.20-1.81 (several peaks, 8H), 2.53 (m, 1H), 3.98 (q, J ) 4.7
Hz, 1H), 4.30 (dddd, J ) 13.4, 2.6, 2.2, 1.0 Hz, 1H), 4.47 (dm,
J ) 13.4 Hz, 1H), 4.85 (q, J ) 2.0 Hz, 1H), 4.90 (ddd, J ) 2.6,
2.6, 1.6 Hz, 1H). 13C NMR δ 21.3, 23.1, 27.1, 27.8, 43.4, 69.8,
77.2, 77.9, 102.5. MS m/ z (relative intensity) 138 (M+, 9.6).
This compound was previously described by Tada16,21 and
Torii.22
4-Meth yl-3-p h en yltetr a h yd r ofu r a n (11): 1H NMR trans-
11 δ 1.03 (d, J ) 6.8 Hz, 3H), 2.38 (m, 1H), 2.88 (m, 1H), 3.48
(dd, J ) 8.9, 8.3 Hz, 1H), 3.82 (t, J ) 8.7 Hz, 1H), 4.20 (m,
2H), 7.18-7.34 (several peaks, 5H). 1H NMR cis-11 δ 0.68 (d,
J ) 7.0 Hz, 3H), 2.63 (m, 1H), 3.39 (m, 1H), 3.53 (t, J ) 8.0
Hz, 1H), 4.06 (dd, J ) 8.2, 7.3 Hz, 1H), 4.13 (dd, J ) 8.6, 4.7
Hz, 1H), 4.19 (dd, J ) 8.6, 6.5 Hz, 1H), 7.18-7.34 (several
peaks, 5H). 13C NMR trans+cis δ 13.3, 15.5, 38.0, 42.6, 48.7,
53.6, 73.0, 73.9, 75.2, 75.5, 126.3, 126.6, 127.5, 128.1, 128.3,
128.5, 140.1, 140.9. MS m/ z (relative intensity) 162 (M+, 21.7).
This compound has previously been described by Ono.12
3-P h en yl-4-isop r op yltetr a h yd r ofu r a n (12): 1H NMR
trans-12 δ 0.83 (d, J ) 6.8 Hz, 3H), 0.88 (d, J ) 6.8 Hz, 3H),
1.69 (m, 1H), 2.19 (dt, J ) 15.8, 8.0 Hz, 1H), 3.08 (q, J ) 7.5
Hz, 1H), 3.65 (t, J ) 8.2 Hz, 1H), 3.73 (dd, J ) 8.7, 7.4 Hz,
1H), 4.07-4.19 (several peaks, 2H), 7.17-7.33 (several peaks,
5H). 1H NMR cis-12 δ 0.76 (d, J ) 6.6 Hz, 3H), 0.89 (d, J )
6.5 Hz, 3H), 1.07 (m, 1H), 2.22 (ddd, J ) 19.5, 11.0, 7.3 Hz,
1H), 3.32 (m, 1H), 3.69 (dd, J ) 10.9, 8.3 Hz, 1H), 4.02 (dd, J
) 8.5, 1.2 Hz, 1H), 4.07 (t, J ) 8.3 Hz, 1H), 4.16 (dd, J ) 8.5,
5.4 Hz, 1H), 7.17-7.33 (several peaks, 5H). 13C NMR trans+cis
δ 20.4, 21.6, 21.7, 22.0, 27.3, 31.1, 47.8, 50.1, 52.7, 54.8, 70.9,
72.5, 76.1, 76.6, 126.2, 126.3, 127.6, 128.2, 128.5, 128.7, 141.9,
143.6. MS m/ z (relative intensity) 190 (M+, 18.3).
2-(3-Bu t en yl)-4-m et h ylen et et r a h yd r ofu r a n (10l): 1H
NMR δ 1.59 (ddt, J ) 13.6, 9.5 Hz, 1H), 1.76 (m, 1H), 2.08-
2.26 (several peaks, 3H), 2.65 (ddddd, J ) 15.5, 5.9, 3.7, 1.8,
1.1 Hz, 1H), 3.95 (ddt, J ) 8.6, 7.0, 5.9 Hz, 1H), 4.24 (dddd, J
) 13.1, 4.7, 2.1, 1.1 Hz, 1H), 4.42 (m, 1H), 4.91 (m, 1H), 4.95-
4.99 (several peaks, 2H), 5.04 (ddt, J ) 17.1, 2.0, 1.6 Hz, 1H),
5.83 (ddt, J ) 17.1, 10.2, 6.6 Hz, 1H). 13C NMR δ 30.3, 34.3,
38.6, 70.7, 79.3, 104.0, 114.7, 138.2, 148.4. The high volatility
of this material precluded an accurate determination of the
yield.
4-Meth ylen e-3-p h en yltetr a h yd r ofu r a n (13): 1H NMR δ
3.80-3.89 (several peaks, 2H), 4.28 (m, 1H), 4.46-4.56 (several
peaks, 2H), 4.77 (m, 1H), 5.05 (m, 1H), 7.21-7.27 (several
peaks, 3H), 7.32 (m, 2H). 13C NMR δ 50.6, 72.0, 76.0, 106.0,
126.7, 128.2, 128.6, 141.0, 152.3. MS m/ z (relative intensity)
160 (M+, 24.1).
2-P h en yl-4-m eth ylen etetr a h yd r ofu r a n (10m ): 1H NMR
δ 2.56 (m, 1H), 2.95 (m, 1H), 4.40 (ddddd, J ) 13.1, 4.7, 2.6,
1.1, 0.4 Hz, 1H), 4.58 (m, 1H), 4.95 (m, 1H), 4.97 (d, J ) 6.1
Hz, 1H), 5.02 (m, 1H), 7.25-7.37 (several peaks, 5H). 13C NMR
δ 41.1, 71.3, 81.1, 104.3, 125.9, 127.6, 128.4, 141.8, 147.9. MS
m/ z (relative intensity) 160 (M+, 23.2). This compound has
previously been prepared by Tada.16,21
2-[(Allyloxy)m eth yl]-4-m eth ylen etetr ah ydr ofu r an (10n ):
1H NMR δ 2.37 (ddddd, J ) 15.7, 8.1, 3.5, 2.2, 1.0 Hz, 1H),
2.61 (ddddd, J ) 15.7, 6.6, 3.7, 1.7, 1.0 Hz, 1H), 3.50 (d, J )
5.3 Hz, 2H), 4.01 (dddd, J ) 12.9, 5.7, 1.5, 1.3 Hz, 1H), 4.03
(dddd, J ) 12.8, 5.6, 1.6, 1.3 Hz, 1H), 4.18 (ddt, J ) 8.0, 6.6,
5.3 Hz, 1H), 4.27 (dddd, J ) 13.0, 4.6, 2.1, 1.1 Hz, 1H), 4.40
(ddddd, J ) 13.1, 3.3, 2.0, 1.0, 0.4 Hz, 1H), 4.91 (dddd, J )
4.8, 2.7, 1.7, 0.4 Hz, 1H), 4.98 (dddd, J ) 4.8, 2.4, 1.9, 0.5 Hz,
1H), 5.17 (ddt, J ) 10.3, 1.8, 1.2 Hz, 1H), 5.27 (dq, J ) 17.2,
1.6 Hz, 1H), 5.91 (ddt, J ) 17.2, 10.3, 5.6 Hz, 1H). 13C NMR
δ 35.1, 71.2, 72.0, 72.4, 78.5, 104.4, 117.1, 134.6, 147.5. MS
m/ z (relative intensity) 154 (M+, 5.0), 113 (M+ - allyl, 14.9).
2-(P h en oxym eth yl)-4-m eth ylen etetr ah ydr ofu r an (10o):
1H NMR δ 2.50 (ddddd, J ) 15.6, 5.5, 3.3, 2.3, 1.0 Hz, 1H),
2.73 (ddddd, J ) 15.7, 6.8, 3.0, 2.0, 1.0 Hz, 1H), 3.99 (dd, J )
9.8, 4.7 Hz, 1H), 4.04 (dd, J ) 9.8, 5.9 Hz, 1H), 4.34 (dddd, J
) 13.0, 4.3, 2.1, 1.0 Hz, 1H), 4.39 (m, 1H), 4.46 (dm, J ) 13.4
2-Eth oxy-4-m eth yltetr ah ydr ofu r an (15a): 1H NMR trans-
15a δ 1.07 (d, J ) 6.5 Hz, 3H), 1.19 (t, J ) 7.1 Hz, 3H), 1.44
(m, 1H), 2.19-2.31 (several peaks, 2H), 3.42 (t, J ) 8.4 Hz,
1H), 3.75 (q, J ) 7.2 Hz, 2H), 3.91 (m, 1H), 5.11 (m, 1H). 13C
NMR trans-15a δ 15.3, 17.2, 32.9, 40.8, 63.1, 73.2, 104.7. 1H
NMR cis-15a δ 1.02 (d, J ) 6.7 Hz, 3H), 1.18 (t, J ) 7.1 Hz,
3H), 1.55 (ddd, J ) 12.9, 8.4, 5.2 Hz, 1H), 2.01 (m, 1H), 2.49
(m, 1H), 3.38 (dd, J ) 8.2, 6.6 Hz, 1H), 3.72 (q, J ) 7.2 Hz,
2H), 4.04 (t, J ) 7.5 Hz, 1H), 5.11 (m, 1H). 13C NMR cis-15a
δ 14.0, 18.4, 31.5, 41.1, 62.6, 73.9, 104.2. MS m/ z (relative
intensity) 129 (M+, 23.8).
2-n -Bu toxy-4-m eth yltetr a h yd r ofu r a n (15b): 1H NMR
trans-15b δ 0.91 (t, J ) 7.4 Hz, 3H), 1.07 (d, J ) 6.7 Hz, 3H),
1.30-1.40 (several peaks, 2H), 1.44 (m, 1H), 1.48-1.58 (several
peaks, 2H), 2.19-2.29 (several peaks, 2H), 3.36 (dt, J ) 9.5,
6.7 Hz, 1H), 3.40 (t, J ) 8.4 Hz, 1H), 3.67 (dt, J ) 9.5, 6.8 Hz,
1H), 3.92 (m, 1H), 5.09 (dd, J ) 5.4, 3.1 Hz, 1H). 13C NMR
trans-15b δ 13.9, 17.4, 19.4, 31.9, 32.8, 40.8, 67.5, 73.2, 104.8.
1H NMR cis-15b δ 0.90 (t, J ) 7.4 Hz, 3H), 1.02 (d, J ) 6.9
Hz, 3H), 1.30-1.40 (several peaks, 2H), 1.48-1.58 (several
peaks, 3H), 2.00 (m, 1H), 2.47 (m, 1H), 3.35 (m, 2H), 3.63 (dd,
J ) 11.9, 9.6 Hz, 1H), 4.02 (dd, J ) 8.0, 7.4 Hz, 1H), 5.08 (m,-
1H). 13C NMR cis-15b δ 13.9, 18.4, 19.4, 31.5, 31.8, 41.1, 67.0,

Tetrahydrofuran Derivatives from Epoxides
J . Org. Chem., Vol. 62, No. 1, 1997 173
73.9, 104.3. MS m/ z (relative intensity) 157 (M+ - 1, 1.0),
101 (M+ - Bu, 2.6), 85 (M+ - BuO, 97.4).
(several peaks, 2H), 3.87 (m, 1H), 4.28 (t, J ) 8.2 Hz, 1H),
5.00 (d, J ) 3.4 Hz, 1H). MS m/ z (relative intensity) 142 (M+,
11.4). This compound has previously been described by Torii.51
2-t-Bu toxy-4-m eth yltetr a h yd r ofu r a n (15c): 1H NMR
trans-15c δ 1.05 (d, J ) 6.3 Hz, 3H), 1.22 (s, 9H), 1.40 (m,
1H), 2.14-2.27 (several peaks, 2H), 3.46 (t, J ) 8.2 Hz, 1H),
3.86 (m, 1H), 5.38 (m, 1H). 13C NMR trans-15c δ 16.9, 28.9,
33.1, 42.0, 73.1, 73.9, 99.6. 1H NMR cis-15c δ 1.00 (d, J ) 6.7
Hz, 3H), 1.21 (s, 9H), 1.57 (ddd, J ) 12.6, 8.4, 5.4 Hz, 1H),
1.92 (ddd, J ) 12.7, 7.3, 1.7 Hz, 1H), 2.49 (m, 1H), 3.31 (dd, J
) 8.1, 6.5 Hz, 1H), 4.07 (dd, J ) 7.9, 7.3 Hz, 1H), 5.39 (m,
1H). 13C NMR cis-15c δ 18.3, 28.9, 31.7, 42.2, 73.6, 73.7, 99.0.
Et3B-Med ia ted Red u ctive Ra d ica l Cycliza tion s. Ex-
cept that 1 equiv of triethylborane (1 M in hexane) was used
as radical initiator instead of AIBN, these cyclizations were
carried out as described in the typical procedure for reductive
radical cyclization. Benzene was replaced by toluene for
reactions carried out at lower than ambient temperatures.
Ack n ow led gm en t. We thank the Swedish Natural
Science Research Council for financial support and the
Swedish Institute for a guest scholarship to V.G.
MS m/ z (relative intensity) 157 (M+ - 1, <0.5), 143 (M+
CH3, 1.5).
-
cis-7-Meth yl-2,9-dioxabicyclo[4.3.0]n on an e (18) 1H NMR
endo-18 δ 0.95 (d, J ) 7.0 Hz, 3H), 1.39 (m, 1H), 1.53-1.72
(several peaks, 3H), 1.88 (m, 1H), 2.42 (m, 1H), 3.59 (dd, J )
9.7, 8.0 Hz, 1H), 3.60 (m, 1H), 3.73 (m, 1H), 3.93 (t, J ) 7.9
Hz, 1H), 5.26 (d, J ) 3.9 Hz, 1H). 13C NMR endo-18 δ 11.6,
19.4, 23.1, 35.1, 37.8, 61.1, 71.6, 102.2. 1H NMR exo-18 δ 1.02
(d, J ) 6.6 Hz, 3H), 1.18-1.41 (several peaks, 2H), 1.59-1.70
(several peaks, 2H), 1.83 (m, 1H), 2.38 (m, 1H), 3.38-3.49
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectra of
compounds 1a -j, 1l, 1n -p , 5a -d , 6d -k , 7c, 7e-j, 9l, 9n -q,
10m -q, 11-13, 14a -c, 15a -c, 17, 18 (56 pages). This
material is contained in libraries on microfiche, immediately
follows this article in the microfilm version of the journal, and
can be ordered from the ACS; see any current masthead page
for ordering information.
(51) Torii, S.; Inokuchi, T.; Yukawa, T. J . Org. Chem. 1985, 50, 5875.
J O961578N