Stereospecific syntheses of 5-alkyl-3-ethoxy-2-((phenylchalcogeno)methylene)tetrahydrofurans

Article abstract of DOI:10.1021/jo961071c

2-Ethoxy-4-(phenylchalcogeno)but-3-ynyl ketones 1-10 were reduced with LiBH₄ in Et₂O diastereoselectively to give 5-(phenylchalcogeno)pent-4-yn-1-ols 11-20. Treatment of the phenylchalcogen-substituted alkynyl alcohols 11-20 with t-BuOK in t-BuOH provided useful (Z)-2-((phenylchalcogeno)methylene)tetrahydrofurans 21-31 stereoselectively.

Full text of DOI:10.1021/jo961071c

8200
J . Org. Chem. 1996, 61, 8200-8206
Ster eosp ecific Syn th eses of
5-Alk yl-3-eth oxy-2-((p h en ylch a lcogen o)m eth ylen e)tetr a h yd r ofu r a n s
Mitsuhiro Yoshimatsu,*,† Motoyo Naito,‡ Hiroshi Shimizu,‡ Osamu Muraoka,§
Genzoh Tanabe,§ and Tadashi Kataoka‡
Gifu University, Faculty of Education, Yanagido, Gifu 501-11, J apan, Gifu Pharmaceutical University,
6-1 Mitahora-higashi 5-chome, Gifu 502, J apan, and Kinki University, Faculty of Pharmaceutical
Sciences, 3-4-1, Kowakae, Higashi-osaka, Osaka 577, J apan
Received J une 6, 1996X
2-Ethoxy-4-(phenylchalcogeno)but-3-ynyl ketones 1-10 were reduced with LiBH4 in Et2O diastereo-
selectively to give 5-(phenylchalcogeno)pent-4-yn-1-ols 11-20. Treatment of the phenylchalcogen-
substituted alkynyl alcohols 11-20 with t-BuOK in t-BuOH provided useful (Z)-2-((phenylchalco-
geno)methylene)tetrahydrofurans 21-31 stereoselectively.
Sch em e 1
Alkynyl sulfides and selenides are synthetic intermedi-
ates of great potential.1 Comasseto et al. reported that
the m-CPBA-oxidation of alkynyl selenides gave the
symmetrical 1,4-disubstituted buta-1,3-diynes in good
yields.2 Recently, it was reported that the Lewis acid-
promoted [2 + 2] cycloaddition reactions of the alkynyl
chalcogenides with electron-deficient olefins proceeded
smoothly and gave cyclobutene derivatives, which could
be further transformed to bicyclo[3.2.1]octenones.3 Alkyn-
yl chalcogenides can lead to vinyl chalcogenides, which
are useful synthetic intermediates,4 by reduction5 or
hydrostannation.6
Ta ble 1. Red u ction s of 3-Eth oxy-1-p h en yl-5-
(p h en ylselen o)p en t-4-yn -1-on e (1)
entry
conditions
% yield (11a :11b)
1
2
3
4
5
6
7
8
9
NaBH4/EtOH/0 °C
NaBH4/Et3B/CH2Cl2/-78 °C
DIBAL/Et2O/-78 °C
DIBAL/ZnCl2/Et2O/-78 °C
DIBAL/LiBr/Et2O/-78 °C
LiAlH4/Et2O/-80 °C
LiAlH4/LiI/Et2O/-80 °C
Zn(BH4)2/Et2O/-78 °C
LiBH4/Et2O/-80 °C
100 (1.2:1)
recover
100 (3:1)
recover
100 (3:1)
100 (2.5:1)
100 (2.5:1)
100 (2:1)
100 (9:1)
Previously, we prepared versatile 3-butynyl ketones7
by R-site-selective reactions of γ-chalcogen-substituted
prop-2-ynyl cations with silyl enol ethers.8 When we
reduced the 3-butynyl ketone 1 with NaBH4 in EtOH at
room temperature, (Z)-2-((phenylseleno)methylenetet-
rahydrofuran 21a was obtained in 21% yield together
with alcohol 11a (68%) (Scheme 1). (Z)-2-Alkenyltet-
rahydrofurans are key intermediates in the synthesis of
prostacyclin PGI2 and have been prepared by mercury(II)-
or palladium(II)-induced cyclization of cis-2-prop-2-ynyl
cyclopentanol.9 Generally, reactions with palladium(II),
mercury(II), or Ag(I) salt have been used for the intramo-
lecular cyclization reactions of alkynyl alcohols,10 and
reactions without a metal catalyst have been reported
to give mixtures of endo- and exo-mode cyclized prod-
ucts.11 Cyclization of 2,4,6-octatriynol with sodium hy-
droxide in methanol has been reported, but the yields
and stereochemistry of the products have not been
described.12 If (Z)-2-alkenyltetrahydrofurans can be
constructed regio- and stereoselectively without a metal
salt catalyst, this novel method will be both practical and
convenient for the syntheses of PGI2 analogues and other
tetrahydrofuran derivatives. Therefore, we undertook a
precise investigation of the synthesis of 2-alkenyltet-
rahydrofurans starting from 4-(phenylchalcogeno)-3-bu-
tynyl ketones. This paper describes the regio- and
stereoselective intramolecular cycloaddition of γ-ynols
promoted by a strong base.
† Gifu University.
‡ Gifu Pharmacetuical University.
§ Kinki University.
X Abstract published in Advance ACS Abstracts, October 15, 1996.
(1) Radchenko, S. I.; Petrov, A. A. Russ. Chem. Rev. 1989, 58, 948.
Lang, H.; Keller, H.; Imhof, W.; Martin, S. Chem. Ber. 1990, 123, 417.
(2) Comasseto, J . V.; Catani, V.; Ferreira, J . T. B.; Braga, A. L. J .
Chem. Soc., Chem. Commun. 1986, 1067.
We first examined the diastereoselective reduction of
â-ethoxy ketone 18 by reference to the literature,13 and
the results are shown in Table 1. The combination of
LiI-LiAlH4 has been reported to bring about the syn-
reduction of â-alkoxy ketones;14 however, this method was
(3) Narasaka, K.; Hayashi, Y.; Shimadzu, H.; Niihata, S. J . Am.
Chem. Soc. 1992, 114, 8869. Hayashi, Y.; Ushio, H.; Narasaka, K.
Chem. Lett. 1994, 289.
(4) Trost, B. M.; Lavoie, A. C. J . Am. Chem. Soc. 1983, 105, 5075.
(5) Comasseto, J . V. J . Organomet. Chem. 1983, 253, 131.
(6) Magriotis, P. A.; Brown, J . T.; Scott, M. E. Tetrahedron Lett.
1991, 32, 5047.
(7) Caine, D.; Tuller, F. N. J . Org. Chem. 1969, 34, 222. Schulte, K.
E.; Reisch, J .; Bergenthal, D. Chem. Ber. 1968, 101, 1540.
(8) Yoshimatsu, M.; Shimizu, H.; Kataoka, T. J . Chem. Soc., Chem.
Commun. 1995, 149.
(11) Bottini, A. T.; Corson, F. P.; Bo¨ttner, E. F. J . Org. Chem. 1965,
30, 2988. Bottini, A. T.; Bo¨ttner, E. F. J . Org. Chem. 1966, 31, 389.
Bottini, A. T.; Maroski, J . G. J . Org. Chem. 1973, 38, 1455. The similar
reactions of other nucleophiles to alkynes have been reported as follows.
Amide nucleophile: Migliorese, K. G.; Tanaka, Y.; Miller, S. I. J . Org.
Chem. 1974, 39, 739. Thiol nucleophile: Williams D. R.; Moore, L. J .
Tetrahedron Lett. 1983, 24, 339.
(9) Riediker, M.; Schwartz, J . J . Am. Chem. Soc. 1982, 104, 5842.
Suzuki, M.; Yanagisawa, A.; Noyori, R. J . Am. Chem. Soc. 1988, 110,
4718.
(10) Harding, K. E.; Tiner, T. H. In Comprehensive Organic Syn-
thesis; Trost, B. M., Ed.; Pergamon Press: New York, 1991; Vol. 4, p
363.
(12) Bohlmann, F.; Herbst, P.; Gleinig, H. Chem. Ber. 1961, 94, 948.
(13) Maier, G.; Seipp, U.; Boses, R. Tetrahedron Lett. 1987, 28, 4515.
Chen, K.-M.; Hardtmann, G. E.; Prasad, K.; Repic, O.; Shapiro, M. J .
Tetrahedron Lett. 1987, 28, 155.
(14) Mori, Y.; Kuhara, M.; Takeuchi, A.; Suzuki, M. Tetrahedron
Lett. 1988, 29, 5419.
S0022-3263(96)01071-7 CCC: $12.00 © 1996 American Chemical Society

2-((Phenylchalcogeno)methylene)tetrahydrofuran Synthesis
J . Org. Chem., Vol. 61, No. 23, 1996 8201
Ta ble 2. Red u ction s of Va r iou s â-Alk oxy Keton es by
Ta ble 4. Cycliza tion Rea ction s of Alk yn yl Alcoh ols w ith
LiBH4 or Na BH4
t-Bu OK
a
(a) syn- and (b) anti-isomer.
Ta ble 3. Cycliza tion Rea ction s of Alk yn yl Alcoh ol 13a
w ith Som e Ba ses
% yield
entry
1
conditions
(23a :23b)
NaH (2 equiv)/THF/15-crown-5/
0 °C/30 min
88 (29:1)
2
3
4
LiH (2 equiv)/THF/15-crown-5/
rt/12 h
t-BuOK (2 equiv)/t-BuOH/
18-crown-6/rt/20 min
t-BuOK (2 equiv)/THF/18-
crown-6/0 °C/30 s
recovery
100 (100:0)
96 (100:0)
gave rise to trans-(Z)-2-((phenylseleno)methylene)-sub-
stituted tetrahydrofuran derivative 21a in 93% yield,
while anti-isomer 11b provided cis-tetrahydrofuran de-
rivative 21b exclusively. Structure assignment of the
product 21a was performed using analytical and NMR
spectral data. The analytical data indicated the molec-
ular formula: C19H20O2Se. The 1H NMR spectrum
exhibited a broad singlet at δ 5.48 due to the character-
istic vinyl proton and two pairs of doublets at δ 2.53 (J
) 5, 13 Hz) and 5.60 (J ) 5, 10 Hz) due to one 4-H and
5-H, respectively. The trans-configuration between the
phenyl group and the ethoxy group of the isomer 21a was
determined by reference to Williams’ report on the
chemical shift method of 3,5-disubstituted tetrahydrofu-
ran derivatives.15 The diastereotopic hydrogens of the
4-position methylene show the largest shift difference at
0.26 ppm for 21b, which has a 3,5-syn relationship in
contrast to that for 21a , which has a 3,5-anti stereo-
chemistry. Moreover, the stereochemical assignment of
the products was supported by a single X-ray analysis of
product 27. â,â-Dimethyl alcohol 12a afforded 4,4-
dimethyltetrahydrofuran derivative 22 (Table 4, entry 3).
not effective with compound 1 (Table 1, entry 7). LiBH4
reduction of the â-ethoxy ketone 1 in Et2O afforded
â-ethoxy alcohols 11a and 11b with good diastereoselec-
tivity (syn:anti ) 9:1, Table 1, entry 9). Therefore, this
reducing agent was used for the reduction of other
â-alkoxy ketones 2-10, and the results are shown in
Table 2. tert-Butyl ketones 3 and 10 were exclusively
reduced to the syn-alcohols 13a and 20a , respectively
(Table 2, entries 3 and 11). p-Nitrophenyl ketone 5 also
gave the syn-alcohol 15a with high stereoselectivity. The
alcohol 16a , obtained from cyclohexane derivative 6, was
converted to p-nitrobenzoate derivative 16′, and its
stereostructure was determined by single-crystal X-ray
analysis.
A brief study on the diastereoselective cyclization of
alkynyl alcohol 13a was conducted employing a few
bases, and the results are shown in Table 3. t-BuOK was
found to be a very suitable base for this cyclization
reaction. The reaction of alkynyl alcohol 13a with
t-BuOK/t-BuOH/18-crown-6 gave (Z)-2-((phenylseleno)-
methylene)tetrahydrofuran derivative 23a diastereose-
lectively (Table 3, entry 3). These reaction conditions
were applied to alkynyl alcohols 11-20, and the results
obtained are shown in Table 4. syn-Alkynyl alcohol 11a
(15) Williams, D. R.; Harigaya, Y.; Moore, J . L.; D’sa, A. J . Am.
Chem. Soc. 1984, 106, 2641. Mihelich, E. D.; Hite, G. A. J . Am. Chem.
Soc. 1992, 114, 7318.

8202 J . Org. Chem., Vol. 61, No. 23, 1996
Yoshimatsu et al.
Sch em e 2
Sch em e 3a
a
Reagents: (i) 3,4-Dihydro-2H-pyran/PPTS; (ii) t-BuOK/t-BuOH/
reflux.
Sch em e 4a
Cyclohexane derivative 16a gave 4-spirocyclohexane
derivative 27 in 83% yield (Table 4, entry 10). Hexynols
17a and 18a furnished 5-methyl-substituted tetrahydro-
furans 28 and 29 in quantitative yields, respectively
(Table 4, entries 11 and 12). (Phenylthio)alkynyl deriva-
tives 19a and 20a also gave 2-((phenylthio)methylene)-
tetrahydrofurans 30 and 31 in good yields, respectively
(Table 4, entries 13 and 14).
In order to determine the reaction intermediate, the
cyclization of 13a was conducted in CD3OD to give
(deuteriomethylene)tetrahydrofuran 24 in 69% yield
(Table 4, entry 5). It has been reported that alkynyl
alcohols isomerize to the corresponding allenic alcohols
under basic conditions to afford oxygen heterocycles upon
cyclization.11,12 Thus, cyclization of â-allenic alcohols
with silver nitrate proceeds in the 6-endo manner to
afford 5,6-dihydro-2H-pyrans,16 while the reaction with
sodium hydroxide in methanol gave 2-alkylidenetetrahy-
drofurans via the 5-exo-mode cyclization.12 If the reaction
described herein proceeded via the allenic intermediate
33 (Scheme 2), the reaction of 13a in CD3OD should have
yielded 3-deuterio-2-(deuteriomethylene)tetrahydrofuran
derivative 35 through the deuteration of the anions 34a
or 34b. The fact that the reaction gave 2-(1-deuterio-
methylene)tetrahydrofuran derivative 24 shows that the
intermediate is the exo-vinyl anion 32. Luo et al.
reported that the intramolecular oxypalladation of acety-
lenic alkoxides17 followed by a cross-coupling reaction
leads to the stereoselective construction of 2-(methylene)-
tetrahydrofurans; however, if our cyclization proceeds via
the direct attack of the alkoxide on the alkynes, the
progression of the reaction without a transition metal
shows that the phenylchalcogeno group of the alkynyl
alcohol would effectively stabilize the transient vinyl
anion intermediate 32. The reaction mechanism was
further examined as described in Schemes 3 and 4. In
order to investigate the potential cyclization reaction of
allenyl alcohol, the alkynyl alcohol 13a was protected as
the THP derivative 36. However, subsequent isomer-
ization of 36 to allene 37 by t-BuOK/t-BuOH was at-
tempted with no success whatsoever. To determine
unequivocally whether this cyclization reaction proceeds
via an allenyl ether intermediate or by the direct addition
of alkoxide to the alkynyl moiety, the 3-deuterated
alkynyl alcohol 42 was specifically prepared (Scheme 4).
Deuterated orthoformate18 was treated with trimethyl-
silyl acetylide to provide (trimethylsilyl)propynal acetal
38, which after desilylation using Bu4NF/EtOH-H2O was
transformed to 39 in satisfactory yield. In turn, the
alkynyl alcohol 42 was obtained according to the proce-
dure described above (Scheme 4). The cyclization of
alcohol 42 afforded the 3-deuterated tetrahydrofuran
derivative 43 quantitatively. These results support our
conclusion that the novel cyclization described in this
paper proceeds via intramolecular oxymetalation of the
acetylenic moiety of the alkynyl alcohol substrates.
The 2-((phenylseleno)alkenyl) group can in principle
be converted to alkyl- and aryl-substituted vinyl deriva-
tives19 and allylsilanes20 by a Ni-catalyzed cross-coupling
reaction. Furthermore, allylic ether derivatives are also
converted to allylic zirconium reagents by Cp2ZrCl2,
which react with aldehydes in a highly diastereoselective
manner to give homoallylic alcohols.21 Hence, the ((phen-
ylseleno)methylene)tetrahydrofurans described herein
can be functionalized at both the vinyl carbon and the
3-position and used as versatile synthetic intermediates.
Exp er im en ta l Section
Melting points were determined on a Yanagimoto micro
melting point apparatus and are uncorrected. Elemental
analyses were performed at the Microanalytical Laboratory
of Gifu Pharmaceutical University. 1H and 13C NMR spectra
were determined with a J EOL GX-270 (270 MHz) or a J EOL
EX-400 (400 MHz) spectrometer at Gifu Pharmaceutical
University and at the Center of Instrumentation of Gifu
University. Chemical shifts are expressed in parts per million
(ppm) with respect to tetramethylsilane as an internal stan-
dard. Splitting patterns are designated as follows: s, singlet;
d, doublet; t, triplet; q, quartet. IR spectra were determined
(18) Sako, M.; Hayashi, T.; Hirota, K.; Maki, Y. Chem. Pharm. Bull.
1992, 40, 1656.
(19) Okamura, H.; Miura, M.; Kosugi, K.; Takei, H. Tetrahedron Lett.
1980, 21, 87.
(16) Chilot, J .-T.; Doutheau, A.; Gore, J . Tetrahedron Lett. 1982, 23,
4693; Bull. Soc. Chim. Fr. 1984, 307.
(20) Hevesi, L.; Hermans, B.; Allard, C. Tetrahedron Lett. 1994, 35,
6729.
(17) Luo, F.-T.; Schreuder, I.; Wang, R.-T. J . Org. Chem. 1992, 57,
2213.
(21) Ito, H.; Taguchi, T.; Hanzawa, Y. Tetrahedron Lett. 1992, 33,
1295.

2-((Phenylchalcogeno)methylene)tetrahydrofuran Synthesis
J . Org. Chem., Vol. 61, No. 23, 1996 8203
on a J ASCO IRA-100 infrared spectrometer and are expressed
in reciprocal centimeters. EI mass spectra (MS) were obtained
using a J EOL J MS-D 300 spectrometer with a direct-insertion
probe at 70 eV. All exact mass determinations were obtained
on the J MA 2000 on-line system.
1.17 (3H, t, J ) 7 Hz), 1.46-1.60 (6H, m), 1.74-1.79 (1H, m),
2.31 (1H, brd, J ) 12 Hz), 2.53 (1H, brd, J ) 14 Hz), 3.31-
3.35 (1H, m), 3.84-3.88 (1H, m), 4.44 (1H, s), 7.22-7.41 (6H,
m), 7.53 (2H, brd, J ) 8 Hz), 7.67 (2H, brd, J ) 8 Hz); 13C
NMR (100 MHz) (CDCl3) δ 14.69 (q), 22.28 (t), 22.96 (t), 25.67
(t), 28.87 (t), 32.60 (t), 56.88 (s), 65.22 (t), 67.77 (s), 78.17 (d),
100.99 (d), 129.41 (d), 129.98 (d), 141.37 (s), 209.42 (s); high-
resolution mass calcd for C24H26O2Se m/ z 426.1098, found m/ z
426.1113.
4-Eth oxy-6-(p h en ylselen o)h ex-5-yn -2-on e (7): a yellow
oil; IR (film, cm-1) 2170 (acetylene), 1720 (CO); 1H NMR (270
MHz) (CDCl3) δ 1.20 (3H, t, J ) 7 Hz), 2.20 (3H, s), 2.78 (1H,
dd, J ) 5, 16 Hz), 2.98 (1H, dd, J ) 8, 16 Hz), 3.43-3.54 (1H,
m), 3.77-3.89 (1H, m), 4.71 (1H, dd, J ) 5, 8 Hz), 7.23-7.35
(3H, m), 7.48-7.52 (2H, m); 13C NMR (100 MHz) (CDCl3) δ
14.97 (q), 30.81 (q), 49.35 (t), 64.79 (t), 66.02 (d), 68.58 (s),
102.05 (s), 127.19 (d), 128.33 (s), 129.07 (d), 129.53 (d), 204.90
(s). A small M+ was observed at m/ z 296 but was too small
for the high-resolution mass spectrum to be measured.
P r ep a r a t ion of Acet ylen ic Ket on es 1-10. Typ ica l
P r oced u r e. BF3‚Et2O (2.47 g, 17.4 mmol) was added drop-
wise to a dry CH2Cl2 (20 mL) solution of 3,3-diethoxy-1-
(phenylseleno)-1-propyne (2.08 g, 7.34 mmol) and 1-((trimeth-
ylsilyl)oxy)styrene (2.52 g, 13.1 mmol) under an Ar atmo-
sphere at -78 °C. The reaction mixture was stirred for 30
min and poured into a saturated NaHCO3 solution (200 mL).
The organic layer was separated, and the aqueous layer was
extracted with CHCl3. The organic layer and the extracts were
combined and dried over MgSO4. The solvent was removed
under reduced pressure. The residue was purified by column
chromatography on silica gel eluting with AcOEt-n-hexane
(1:20). 3-Ethoxy-1-phenyl-5-(phenylseleno)pent-4-yn-1-one (1)
(1.95 g, 63%) was obtained as a yellow oil.
3-E t h oxy-1-p h en yl-5-(p h en ylselen o)p en t -4-yn -1-on e
(1): a yellow oil; IR (film, cm-1) 2170 (acetylene), 1680 (CO);
1H NMR (400 MHz) (CDCl3) δ 1.20 (3H, t, J ) 7 Hz), 3.32 (1H,
dd, J ) 5, 16 Hz), 3.51-3.60 (1H, m), 3.55 (1H, dd, J ) 5, 16
Hz), 3.83-3.90 (1H, m), 4.94 (1H, dd, J ) 5, 8 Hz), 7.21-7.29
(2H, m), 7.43-7.57 (6H, m), 7.95-7.97 (2H, m); 13C NMR (100
MHz) (CDCl3) δ 15.03 (q), 44.79 (t), 64.89 (t), 65.73 (s), 66.28
(d), 102.52 (s), 128.24 (d), 128.38 (s), 128.60 (d), 129.00 (d),
129.50 (d), 133.28 (d), 136.83 (s), 196.23 (s). Anal. Calcd for
C19H18O2Se: C, 63.87; H, 5.08. Found: C, 63.66; H, 5.08.
2,2-Dim eth yl-3-eth oxy-1-p h en yl-5-(p h en ylselen o)p en t-
4-yn -1-on e (2): a yellow oil; IR (film, cm-1) 2170 (acetylene),
3,3-Dim e t h yl-4-e t h oxy-6-(p h e n ylse le n o)h e x-5-yn -2-
on e (8): a yellow oil; IR (film, cm-1) 2160 (acetylene), 1710
1
(CO); H NMR (270 MHz) (CDCl3) δ 1.17 (3H, t, J ) 7 Hz),
1.18 (3H, s), 1.25 (3H, s), 2.18 (3H, s), 3.36-3.47 (1H, m), 3.76-
3.88 (1H, m), 4.47 (1H, s), 7.17-7.40 (3H, m), 7.49-7.60 (2H,
m); 13C NMR (67.5 MHz) (CDCl3) δ 14.84 (q), 19.44 (q), 22.19
(q), 26.49 (q), 65.19 (t), 75.73 (s), 76.18 (d), 100.81 (s), 127.15
(d), 129.14 (d), 129.51 (s), 129.55 (d), 211.58 (s). A small M+
was observed at m/ z 324 but was too small for the high-
resolution mass spectrum to be measured.
3-Eth oxy-1-p h en yl-5-(p h en ylth io)p en t-4-yn -1-on e (9):
1
a yellow oil; IR (film, cm-1) 2170 (acetylene), 1680 (CO); H
1
1680 (CO); H NMR (400 MHz) (CDCl3) δ 1.12 (3H, t, J ) 7
NMR (400 MHz) (CDCl3) δ 1.20 (3H, t, J ) 7 Hz), 3.33 (1H,
dd, J ) 5, 16 Hz), 3.51-3.62 (2H, m), 3.83-3.90 (1H, m), 4.96
(1H, dd, J ) 5, 7 Hz), 7.18-7.22 (1H, m), 7.24-7.32 (2H, m),
7.37-7.40 (2H, m), 7.42-7.46 (2H, m), 7.53-7.57 (1H, m),
7.95-7.97 (2H, m); 13C NMR (100 MHz) (CDCl3) δ 14.95 (q),
44.63 (t), 64.80 (t), 66.10 (d), 72.36 (s), 97.67 (s), 126.14 (d),
126.49 (d), 128.15 (d), 128.54 (d), 129.14 (d), 132.40 (s), 133.24
(d), 136.73 (s), 196.07 (s); MS m/ z 309 (M+ - 1). Anal. Calcd
for C19H18O2S: C, 73.52; H, 5.84. Found: C, 73.29; H, 5.82.
2,2-Dim et h yl-5-et h oxy-6-(p h en ylt h io)h ep t -7-yn -3-on e
(10): a yellow oil; IR (film, cm-1) 2170 (acetylene), 1710 (CO);
1H NMR (400 MHz) (CDCl3) δ 1.14 (9H, s), 1.20 (3H, t, J ) 7
Hz), 2.83 (1H, dd, J ) 5, 17 Hz), 3.11 (1H, dd, J ) 8, 17 Hz),
3.46-3.50 (1H, m), 3.80-3.84 (1H, m), 4.78 (1H, dd, J ) 5, 8
Hz), 7.31-7.40 (5H, m); 13C NMR (100 MHz) (CDCl3) δ 15.00
(q), 25.90 (q), 42.93 (t), 44.14 (s), 64.89 (t), 66.25 (d), 71.90 (s),
97.90 (s), 126.16 (d), 126.52 (d), 129.18 (d), 132.45 (s), 211.66
(s); MS m/ z 289 (M+ - 1). Anal. Calcd for C17H22O2S: C,
70.31; H, 7.64. Found: C, 70.00; H, 7.45.
P r ep a r a tion of Alk yn yl Alcoh ols 11a ,b-20a , Typ ica l
P r oced u r e. An Et2O (3 mL) solution of 3-ethoxy-1-phenyl-
5-(phenylseleno)pent-4-yn-1-one (1) (0.10 g, 0.28 mmol) was
added dropwise to an Et2O suspension of LiBH4 (0.01 g, 0.60
mmol) under an Ar atmosphere at -80 °C. The reaction
mixture was stirred for 10 min and poured into water (100
mL). The organic layer was separated, and the aqueous layer
was extracted with ether. The organic layer and the extracts
were combined and dried over MgSO4. The solvent was
removed under reduced pressure. The residue was purified
by preparative TLC on silica gel eluting with AcOEt-n-hexane
(1:10) and afforded (1S*,3R*)- (11a ) and (1R*,3R*)-3-ethoxy-
1-phenyl-5-(phenylseleno)pent-4-yn-1-ol (11b) (0.1 g, 100%) as
a pale yellow oil.
(1S*,3R*)-3-E t h oxy-1-p h en yl-5-(p h en ylselen o)p en t -4-
yn -1-ol (11a ): a colorless oil; IR (film, cm-1) 3700-3200 (OH),
2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ 1.24 (3H, t, J
) 7 Hz), 2.04-2.09 (1H, m), 2.25-2.33 (1H, m), 3.43-3.50 (2H,
m), 3.84-3.90 (1H, m), 4.44 (1H, dd, J ) 5, 9 Hz), 4.92 (1H,
dd, J ) 4, 9 Hz), 7.22-7.34 (8H, m), 7.47-7.51 (2H, m). 13C
NMR (100 MHz) (CDCl3) δ 15.10 (q), 45.00 (t), 64.70 (t), 66.25
(s), 69.82 (d), 72.89 (d), 102.13 (s), 125.72 (d), 127.13 (d), 127.49
(d), 128.23 (s), 128.37 (d), 128.96 (d), 129.49 (d), 143.75 (s).
Anal. Calcd for C19H20O2Se: C, 63.56; H, 5.61. Found: C,
63.82; H, 5.68.
Hz), 1.40 (3H, s), 1.42 (3H, s), 3.23-3.28 (1H, m), 3.75-3.81
(1H, m), 4.66 (1H, s), 7.24-7.55 (10H, m); 13C NMR (100 MHz)
(CDCl3) δ 14.85 (q), 20.65 (q), 23.50 (q), 52.38 (s), 65.18 (t),
66.84 (s), 76.46 (d), 100.86 (s), 126.90 (d), 128.51 (s), 129.06
(d), 129.53 (d), 130.30 (d), 139.89 (s), 208.83 (s); MS m/ z 386
(small M+). Anal. Calcd for C21H22O2Se: C, 65.45; H, 5.75.
Found: C, 65.19; H, 5.70.
2,2-Dim et h yl-5-et h oxy-7-(p h en ylselen o)h ep t -6-yn -3-
on e (3): a yellow oil; IR (film, cm-1) 2125 (acetylene), 1700
1
(CO); H NMR (400 MHz) (CDCl3) δ 1.13 (9H, s), 1.18 (3H, t,
J ) 7 Hz), 2.81 (1H, dd, J ) 5, 17 Hz), 3.12 (1H, dd, J ) 8 and
17 Hz), 3.42-3.49 (1H, m), 3.78-3.84 (1H, m), 4.78 (1H, dd, J
) 5, 8 Hz), 7.25-7.38 (3H, m), 7.49-7.57 (2H, m); 13C NMR
(100 MHz) (CDCl3) δ 15.05 (q), 25.93 (q), 43.03 (t), 44.17 (s),
64.92 (t), 65.22 (s), 66.40 (d), 102.71 (s), 127.12 (d), 128.58 (s),
129.02 (d), 129.50 (d), 130.38 (d), 211.74 (s); MS m/ z 337 (M+-
1). Anal. Calcd for C17H22O2Se: C, 60.53; H, 6.57. Found:
C, 60.24; H, 6.46.
1-(p -Br om op h en yl)-3-et h oxy-5-(p h en ylselen o)p en t -4-
yn -1-on e (4): a yellow oil; IR (film, cm-1) 2170 (acetylene),
1
1690 (CO); H NMR (400 MHz) (CDCl3) δ 1.19 (3H, t, J ) 7
Hz), 3.27 (1H, dd, J ) 5, 17 Hz), 3.49-3.55 (2H, m), 3.82-
3.88 (1H, m), 4.90 (1H, dd, J ) 5, 8 Hz), 7.25-7.30 (3H, m),
7.48 (2H, brd, J ) 6 Hz), 7.58 (2H, d, J ) 9 Hz), 7.81 (2H, d,
J ) 9 Hz); 13C NMR (100 MHz) (CDCl3) δ 14.97 (q), 44.65 (t),
64.88 (t), 66.01 (s), 66.19 (d), 102.15 (s), 127.13 (d), 128.23 (s),
128.48 (s), 129.03 (d), 129.49 (d), 129.76 (d), 131.87 (d), 135.54
(s), 195.29 (s); MS m/ z 436 (M+ - 1). Anal. Calcd for C19H17
BrO2Se: C, 52.32; H, 3.93. Found: C, 52.10; H, 3.96.
-
3-Eth oxy-1-(p-n itr op h en yl)-5-(p h en ylselen o)p en t-4-yn -
1-on e (5): yellow needles; mp 55-56 °C; IR (KBr, cm-1) 2170
(acetylene), 1700 (CO), 1540, 1340 (NO2); 1H NMR (400 MHz)
(CDCl3) δ 1.19 (3H, t, J ) 7 Hz), 3.34 (1H, dd, J ) 5, 16 Hz),
3.49-3.55 (1H, m), 3.60 (1H, dd, J ) 8, 16 Hz), 3.84-3.91 (1H,
m), 4.90 (1H, dd, J ) 5, 8 Hz), 7.26-7.32 (3H, m), 7.48 (2H, d,
J ) 8 Hz), 8.12 (2H, d, J ) 8 Hz), 8.28 (2H, d, J ) 8 Hz); 13C
NMR (100 MHz) (CDCl3) δ 14.98 (q), 45.19 (t), 65.01 (t), 66.17
(d), 66.59 (s), 101.70 (s), 123.81 (d), 127.28 (d), 128.11 (s),
129.13 (d), 129.33 (d), 129.57 (d), 141.28 (s), 150.35 (s), 195.12
(s). Anal. Calcd for C19H17NO4Se: C, 56.72; H, 4.26; N, 3.48.
Found: C, 56.94; H, 4.33; N, 3.56.
1-Ben zoyl-1-(1-eth oxy-3-(p h en ylselen o)p r op -2-yn yl)cy-
cloh exa n e (6): a yellow oil; IR (film, cm-1) 2170 (acetylene),
1
1680 (CO); H NMR (400 MHz) (CDCl3) δ 1.05-1.19 (1H, m),

8204 J . Org. Chem., Vol. 61, No. 23, 1996
Yoshimatsu et al.
(1R*,3R*)-3-E t h oxy-1-p h en yl-5-(p h en ylselen o)p en t -4-
yn -1-ol (11b): a colorless oil; IR (film, cm-1) 3600-3200 (OH),
2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ 1.27 (3H, J )
7 Hz), 2.20-2.24 (2H, m), 3.42-3.50 (2H, m), 3.86-3.93 (1H,
m), 4.47 (1H, dd, J ) 4, 6 Hz), 5.13 (1H, brs), 7.25-7.38 (8H,
m), 7.52-7.54 (2H, m); high-resolution mass calcd for C19H20O2-
Se m/ z 360.0628, found m/ z 360.0636.
3.95 (1H, m), 4.44 (1H, s), 4.80 (1H, d, J ) 7 Hz), 7.19-7.28
(6H, m), 7.35-7.39 (4H, m); 13C NMR (100 MHz) (CDCl3) δ
14.93 (q), 21.42 (t), 21.50 (t), 25.65 (t), 29.84 (t), 30.82 (t), 44.69
(s), 65.28 (t), 68.73 (s), 74.48 (d), 78.46 (d), 100.70 (s), 126.80
(d), 126.96 (d), 127.04 (d), 128.08 (d), 128.79 (d), 129.27 (d),
141.41 (s). Anal. Calcd for C24H28O2Se: C, 67.44; H, 6.60.
Found: C, 67.27; H, 6.75.
(1R*,3R*)- an d (1S*,3R*)-2,2-Dim eth yl-3-eth oxy-1-ph en -
yl-5-(p h en ylselen o)p en t-4-yn -1-ol (12a ,b): 12a :12b ) 5.2:
1; a colorless oil; IR (film, cm-1) 3600-3200 (OH), 2170
(acetylene); 1H NMR (400 MHz) (CDCl3) δ 0.80 (s), 0.98 (s),
1.27 (t, J ) 7 Hz), 3.43-3.51 (m), 3.78 (brs), 3.88-3.96 (m),
4.16 (s), 4.18 (s), 4.73 (s), 4.84 (s), 7.20-7.32 (m), 7.49-7.51
(m); 13C NMR of 12a (100 MHz) (CDCl3) δ 15.06 (q), 15.64 (q),
21.92 (q), 43.13 (s), 66.74 (t and s), 79.94 (d), 80.58 (d), 101.03
(s), 127.15 (d), 127.42 (d), 127.55 (d), 128.01 (d), 128.55 (s),
129.07 (d), 129.51 (d), 141.10 (s). Anal. Calcd for C21H24O2-
Se: C, 65.11; H, 6.30. Found: C, 64.99; H, 6.30.
(2R*,4R*)- a n d (2S*,4R*)-4-eth oxy-6-(p h en ylselen o)-
h ex-5-yn -2-ol (17a ,b): 17a :17b ) 7:1; a yellow oil; IR (film,
cm-1) 3650-3200 (OH), 2150 (acetylene); 1H NMR (270 MHz)
(CDCl3) δ 1.19 (d, J ) 6 Hz), 1.21 (t, J ) 7 Hz), 1.22 (t, J ) 7
Hz), 1.24 (t, J ) 7 Hz), 1.82-2.04 (m), 3.19 (brs), 3.43-3.54
(m), 3.81-3.89 (m), 3.98-4.11 (m), 4.19-4.21 (m), 4.45 (dd, J
) 5, 8 Hz), 4.53 (dd, J ) 5, 6 Hz), 7.20-7.33 (m), 7.46-7.51
(m); 13C NMR (67.5 MHz) (CDCl3) δ 14.92 (q), 23.28 (q), 44.31
(t), 64.42 (t), 65.80 (s), 66.42 (d), 69.81 (d), 102.27 (s), 126.97
(d), 128.16 (s), 128.78 (d), 129.35 (d); high-resolution mass calcd
for C14H18O2Se m/ z 298.0472, found m/ z 298.0465.
(3S*,5R*)-2,2-Dim eth yl-5-eth oxy-7-(p h en ylselen o)h ep t-
6-yn -3-ol (13a ): a colorless oil; IR (film, cm-1) 3650-3200
(OH), 2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ 0.91 (9H,
s), 1.25 (3H, t, J ) 7 Hz), 1.87-1.97 (2H, m), 3.09 (1H, brs),
3.47-3.53 (2H, m), 3.89-3.90 (1H, m), 4.46 (1H, dd, J ) 5, 9
Hz), 7.26-7.34 (3H, m), 7.51 (2H, d, J ) 7 Hz); 13C NMR (100
MHz) (CDCl3) δ 15.10 (q), 25.57 (q), 34.70 (s), 37.75 (t), 64.88
(t), 65.97 (s), 71.11 (d), 78.68 (d), 102.44 (s), 127.16 (d), 128.30
(s), 128.99 (d), 129.52 (d); high-resolution mass calcd for
C17H24O2Se m/ z 340.0941, found m/ z 340.0957.
(3R*,5R*)-2,2-Dim eth yl-5-eth oxy-7-(p h en ylselen o)h ep t-
6-yn -3-ol (13b): a colorless oil; IR (film, cm-1) 3700-3100
(OH), 2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ 0.91 (9H,
s), 1.23 (3H, t, J ) 7 Hz), 1.79-1.86 (1H, m), 1.92-1.96 (1H,
m), 2.85 (1H, brs), 3.43-3.50 (1H, m), 3.73-3.75 (1H, m), 3.84-
3.90 (1H, m), 4.59-4.61 (1H, m), 7.26-7.33 (3H, m), 7.52-
7.54 (2H, m); high-resolution mass calcd for C17H24O2Se m/ z
340.0941, found m/ z 340.0958.
(1S*,3R*)-1-(p-Br om op h en yl)-3-et h oxy-5-(p h en ylsele-
n o)p en t-4-yn -1-ol (14a ): a colorless oil; IR (film, cm-1) 3600-
3200 (OH), 2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ
1.26 (3H, t, J ) 7 Hz), 2.01-2.20 (1H, m), 2.23-2.28 (1H, m),
3.46-3.53 (1H, m), 3.61 (1H, brs), 3.86-3.94 (1H, m), 4.47 (1H,
dd, J ) 5, 9 Hz), 4.83-4.90 (1H, m), 7.20-7.31 (5H, m), 7.44
(2H, d, J ) 8 Hz), 7.48 (2H, dd, J ) 1, 8 Hz). 13C NMR (100
MHz) (CDCl3) δ 15.06 (q), 44.85 (t), 64.75 (t), 66.58 (s), 69.78
(d), 72.34 (d), 101.74 (s), 121.18 (s), 127.44 (d), 128.10 (s),
128.99 (d), 129.51 (d), 131.39 (d), 142.76 (s); high-resolution
mass calcd for C19H19BrO2Se m/ z 437.9733, found m/ z
437.9712.
(1R*,3R*)-1-(p-Br om op h en yl)-3-eth oxy-5-(p h en ylsele-
n o)p en t-4-yn -1-ol (14b): a colorless oil; IR (film, cm-1) 3650-
3100 (OH), 2170 (acetylene); 1H NMR (400 MHz) (CDCl3) δ
1.26 (3H, t, J ) 7 Hz), 2.13-2.18 (2H, m), 3.43-3.48 (1H, m),
3.61 (1H, brs), 3.85-3.91 (1H, m), 4.44-4.47 (1H, m), 5.02-
5.08 (1H, m), 7.21-7.40 (5H, m), 7.45 (2H, d, J ) 8 Hz), 7.51
(2H, d, J ) 8 Hz); 13C NMR (100 MHz) (CDCl3) δ 15.08 (q),
43.97 (t), 64.97 (t), 66.92 (s), 68.64 (d), 70.73 (d), 101.63 (s),
120.96 (s), 127.27 (d), 127.37 (d), 128.19 (s), 129.14 (d), 129.54
(2R*,4R*)-3,3-Dim eth yl-4-eth oxy-6-(p h en ylselen o)h ex-
5-yn -2-ol (18a ): a yellow oil; IR (film, cm-1) 3650-3200 (OH),
1
2170 (acetylene); H NMR (270 MHz) (CDCl3) δ 0.93 (3H, s),
1.06 (3H, s), 1.12 (3H, d, J ) 6 Hz), 1.24 (3H, t, J ) 7 Hz),
3.38-3.53 (1H, m), 3.77-3.98 (2H, m), 4.16 (1H, s), 7.19-7.34
(3H, m), 7.49-7.53 (2H, m); 13C NMR (67.5 MHz) (CDCl3) δ
15.39 (q), 15.50 (q), 18.34 (q), 22.41 (q), 42.77 (s), 65.72 (t),
66.92 (s), 74.51 (d), 80.70 (d), 101.59 (s), 127.55 (d), 129.20 (s),
129.50 (d), 129.92 (d). A small M+ was observed at m/ z 326
but was too small for the high-resolution mass spectrum to be
measured.
(1S*,3R*)- a n d (1R*,3R*)-3-et h oxy-1-p h en yl-5-(p h en -
ylth io)p en t-4-yn -1-ol (19a ,b): 19a :19b ) 6:1; a yellow oil;
IR (film, cm-1) 3650-3100 (OH), 2170 (acetylene); 1H NMR
(400 MHz) (CDCl3) δ 1.26 (t, J ) 7 Hz), 1.27 (t, J ) 7 Hz),
2.08-2.13 (m), 2.20-2.23 (m), 3.42 (s), 3.45-3.54 (m), 3.84-
3.93 (m), 4.45-4.50 (m), 4.93 (dd, J ) 3, 9 Hz), 5.11-5.12 (m),
7.07-7.45 (m); 13C NMR of 19a (100 MHz) (CDCl3) δ 15.12
(q), 44.97 (t), 64.76 (t), 68.45 (s), 69.77 (d), 72.93 (d), 97.42 (s),
125.79 (d), 126.17 (d), 126.64 (d), 128.44 (d), 129.28 (d), 132.30
(s), 143.78 (s). Anal. Calcd for C19H20O2S: C, 63.51; H, 5.61.
Found: C, 63.39; H, 5.64.
(3S*,5R*)-2,2-Dim eth yl-5-eth oxy-7-(p h en ylth io)h ep t-6-
yn -3-ol (20a ): a yellow oil; IR (film, cm-1) 3700-3200 (OH),
1
2180 (acetylene); H NMR (400 MHz) (CDCl3) δ 0.91 (9H, s),
1.24 (3H, t, J ) 7 Hz), 1.88-1.93 (1H, m), 1.96-2.00 (1H, m),
3.15 (1H, brs), 3.48-3.52 (2H, m), 3.88-3.91 (1H, m), 4.47 (1H,
dd, J ) 6, 8 Hz), 7.19-7.22 (1H, m), 7.30-7.33 (2H, m), 7.38-
7.41 (2H, m); 13C NMR (100 MHz) (CDCl3) δ 14.99 (q), 25.74
(q), 34.57 (s), 37.61 (t), 64.67 (t), 70.78 (d), 72.52 (s), 78.34 (d),
97.63 (s), 125.99 (d), 126.47 (d), 129.10 (d), 132.25 (s); high-
resolution mass calcd for C17H24O2S m/ z 292.1597, found m/ z
292.1501.
Cycliza tion Rea ction s of Alk yn yl Alcoh ols 11a -20a .
Typ ica l P r oced u r e. t-BuOK (47 mg, 0.42 mmol) was added
to a t-BuOH (1 mL) solution of (1S*,3R*)-3-ethoxy-1-phenyl-
5-(phenylseleno)pent-4-yn-1-ol (11a ) (76 mg, 0.21 mmol). The
mixture was stirred for 30 min. The solvent was removed
under reduced pressure. The residue was poured into water
(70 mL) and extracted with ether. The extracts were dried
over MgSO4. The solvent was removed under reduced pres-
sure. The residue was purified by preparative TLC on silica
gel eluting with AcOEt-n-hexane (1:50). (Z)-(3R*,5S*)-3-
Ethoxy-5-phenyl-2-((phenylseleno)methylene)tetrahydro-
furan (21a ) (71 mg, 93%) was obtained as a yellow oil: IR (film,
cm-1) 1650, 1240, 1090 (COC); 1H NMR (400 MHz) (CDCl3) δ
1.25 (3H, t, J ) 7 Hz), 2.04-2.11 (1H, m), 2.53 (1H, dd, J ) 5,
13 Hz), 3.42-3.48 (1H, m), 3.71-3.77 (1H, m), 4.37 (1H, brd,
J ) 4 Hz), 5.48 (1H, s), 5.60 (1H, dd, J ) 5, 10 Hz), 7.19-7.34
(8H, m), 7.51-7.53 (2H, m); 13C NMR (100 MHz) (CDCl3) δ
15.13 (q), 42.24 (t), 63.94 (t), 78.94 (d), 82.83 (d), 86.38 (d),
125.54 (d), 126.40 (d), 127.88 (d), 128.46 (d), 129.03 (d), 131.08
(d), 131.83 (s), 140.48 (s), 158.29 (s). Anal. Calcd for C19H20O2-
Se: C, 63.51; H, 5.61. Found: C, 63.62; H, 5.59.
(d), 131.39 (d), 142.93 (s); high-resolution mass calcd for C19H19
-
BrO2Se m/ z 437.9734, found m/ z 437.9714.
(1S*,3R*)- a n d (1R*,3R*)-3-eth oxy-1-(p-n itr op h en yl)-5-
(p h en ylselen o)-p en t-4-yn -1-ol (15a ,b): 15a :15b ) 15:1; a
yellow oil; IR (film, cm-1) 3700-3200 (OH), 2170 (acetylene),
1
1520, 1350 (NO2); H NMR (400 MHz) (CDCl3) δ 1.26 (t, J )
7 Hz), 2.07-2.14 (m), 2.15-2.27 (m), 3.44-3.56 (m), 3.88-3.95
(m), 3.40 (brs), 4.50-4.53 (m), 4.54 (dd, J ) 5, 9 Hz), 5.04 (brd,
J ) 9 Hz), 5.21-5.23 (m), 7.23-7.31 (m), 7.47-7.52 (m), 8.14
(d, J ) 8 Hz); 13C NMR of 15a (100 MHz) (CDCl3) δ 14.93 (q),
44.59 (t), 64.71 (t), 66.96 (s), 69.56 (d), 71.93 (d), 101.31 (s),
123.43 (d), 126.36 (d), 127.18 (d), 128.94 (d), 129.43 (d), 146.97
(s), 151.09 (s); high-resolution mass calcd for C19H19NO4Se m/ z
405.0479, found m/ z 405.0460.
(1R*,3R*)-3-E t h oxy-2,2-p en t a m et h ylen e-1-p h en yl-5-
(p h en ylselen o)p en t-4-yn -1-ol (16a ): a yellow oil; IR (film,
cm-1) 3620-3200 (OH), 2170 (acetylene); 1H NMR (400 MHz)
(CDCl3) δ 1.25 (3H, t, J ) 7 Hz), 1.32-1.59 (8H, m), 1.82-
2.01 (2H, m), 3.37-3.41 (1H, m), 3.83 (1H, d, J ) 7 Hz), 3.90-
(Z)-(3R *,5R *)-3-E t h oxy-5-p h e n yl-2-((p h e n ylse le n o)-
m eth ylen e)tetr a h yd r ofu r a n (21b): a yellow oil; IR (film,
cm-1) 1650, 1240, 1090 (COC); 1H NMR (400 MHz) (CDCl3) δ
1.21 (3H, t, J ) 7 Hz), 2.01-2.09 (1H, m), 2.73-2.79 (1H, m),

2-((Phenylchalcogeno)methylene)tetrahydrofuran Synthesis
J . Org. Chem., Vol. 61, No. 23, 1996 8205
3.52-3.66 (2H, m), 4.61 (1H, brt, J ) 6 Hz), 5.30 (1H, dd, J )
6, 9 Hz), 5.48 (1H, d, J ) 2 Hz), 7.17-7.32 (8H, m), 7.49-7.52
(2H, m); 13C NMR (100 MHz) (CDCl3) δ 15.29 (q), 40.41 (t),
65.08 (t), 78.66 (d), 81.37 (d), 83.44 (d), 125.79 (d), 126.18 (d),
127.90 (d), 128.37 (d), 128.96 (d), 130.77 (d), 132.14 (s), 140.55
(s), 159.26 (s); high-resolution mass calcd for C19H20O2Se m/ z
360.0628, found m/ z 360.0647.
(Z )-(3R *,5S *)-4,4-D i m e t h y l-3-e t h o x y -5-p h e n y l-2-
((p h en ylselen o)m eth ylen e)tetr a h yd r ofu r a n (22): a yel-
low oil; IR (film, cm-1) 1640, 1260, 1090 (COC); 1H NMR (400
MHz) (CDCl3) δ 0.59 (3H, s), 1.14 (3H, s), 1.24 (3H, t, J ) 7
Hz), 3.36-3.44 (1H, m), 3.76 (1H, s), 3.77-3.85 (1H, m), 5.29
(1H, s), 5.47 (1H, s), 7.18-7.31 (8H, m), 7.52-7.54 (2H, m);
13C NMR (100 MHz) (CDCl3) δ 15.06 (q), 18.41 (q), 20.49 (q),
46.22 (s), 64.16 (t), 86.18 (d), 86.84 (d), 89.13 (d), 126.12 (d),
126.55 (d), 127.80 (d), 129.03 (d), 130.84 (d), 132.33 (s), 136.60
(s), 158.66 (s); high-resolution mass calcd for C21H24O2Se m/ z
388.0942, found m/ z 388.0930.
(Z)-(3R*,5S*)-5-ter t-Bu tyl-3-eth oxy-2-((p h en ylselen o)-
m eth ylen e)tetr a h yd r ofu r a n (23a ): a yellow oil; IR (film,
cm-1) 1640, 1240, 1090 (COC); 1H NMR (400 MHz) (CDCl3) δ
0.90 (9H, s), 1.21 (3H, t, J ) 7 Hz), 1.87-1.94 (1H, m), 2.00-
2.05 (1H, m), 3.35-3.42 (1H, m), 3.67-3.74 (1H, m), 4.24 (1H,
brd, J ) 5 Hz), 4.34 (1H, dd, J ) 5, 10 Hz), 5.31 (1H, s), 7.17-
7.25 (3H, m), 7.47-7.49 (2H, m); 13C NMR (100 MHz) (CDCl3)
δ 15.40 (q), 25.51 (q), 33.80 (s), 34.24 (t), 64.01 (t), 79.57 (d),
85.52 (d), 89.70 (d), 126.54 (d), 129.23 (d), 131.29 (d), 132.33
(s), 158.80 (s); high-resolution mass calcd for C17H24O2Se m/ z
340.0941, found m/ z 340.0925.
(Z)-(3R*,5S*)-3-Eth oxy-5-(p-n itr op h en yl)-2-((p h en ylse-
len o)m eth ylen e)tetr a h yd r ofu r a n (26): a yellow oil; IR
(film, cm-1) 1640, 1520, 1340 (NO2), 1220, 1080 (COC); 1H
NMR (400 MHz) (CDCl3) δ 1.26 (3H, t, J ) 7 Hz), 1.98-2.04
(1H, m), 2.63 (1H, dd, J ) 5, 13 Hz), 3.44-3.48 (1H, m), 3.74-
3.78 (1H, m), 4.39 (1H, brd, J ) 5 Hz), 5.56 (1H, s), 5.69 (1H,
dd, J ) 5, 10 Hz), 7.44-7.47 (3H, m), 7.45 (2H, d, J ) 8 Hz),
7.53 (2H, d, J ) 7 Hz), 8.20 (2H, d, J ) 8 Hz); 13C NMR (100
MHz) (CDCl3) δ 15.10 (q), 42.27 (t), 64.02 (t), 78.54 (d), 81.59
(d), 87.96 (d), 123.84 (d), 126.12 (d), 126.71 (d), 129.16 (d),
131.35 (d), 147.48 (s), 147.98 (s), 157.27 (s); high-resolution
mass calcd for C19H19NO4Se m/ z 405.0475, found m/ z 405.0454.
(Z)-(3R *,5S *)-3-E t h oxy-5-p h e n yl-2-((p h e n ylse le n o)-
m e t h y le n e )t e t r a h y d r o fu r a n -4-s p ir o -1′-c y c lo h e x a n e
(27): colorless prisms; mp 73-78 °C; IR (KBr, cm-1) 1640,
1100, 1000 (COC); 1H NMR (400 MHz) (CDCl3) δ 0.57 (1H, dt,
J ) 4, 14 Hz), 0.92-0.95 (1H, m), 1.03-1.10 (1H, m), 1.23-
1.50 (3H, m), 1.25 (3H, t, J ) 7 Hz), 1.54-1.64 (3H, m), 2.13
(1H, brd, J ) 13 Hz), 3.37-3.45 (1H, m), 3.82-3.89 (1H, m),
4.13 (1H, s), 5.22 (1H, s), 5.47 (1H, s), 7.16-7.20 (2H, m), 7.21-
7.29 (6H, m), 7.52 (2H, d, J ) 8 Hz); 13C NMR (100 MHz)
(CDCl3) δ 15.09 (q), 22.44 (t), 23.12 (t), 25.64 (t), 27.10 (t), 27.98
(t), 49.82 (s), 64.12 (t), 81.84 (d), 86.25 (d), 90.05 (d), 126.30
(d), 126.75 (d), 127.78 (d), 129.06 (d), 130.91 (d), 132.24 (s),
136.52 (s), 158.65 (s); Anal. Calcd for C24H28O2Se: C, 67.44;
H, 6.60. Found: C, 67.36; H, 6.61.
(Z)-(3R *,5R *)-3-E t h oxy-5-m e t h yl-2-((p h e n ylse le n o)-
m eth ylen e)tetr a h yd r ofu r a n (28): a yellow oil; IR (film,
cm-1) 1650, 1250, 1100 (COC); 1H NMR (270 MHz) (CDCl3) δ
1.20 (3H, t, J ) 7 Hz), 1.35 (3H, d, J ) 6 Hz), 1.70-1.80 (1H,
m), 2.23 (1H, ddd, J ) 1, 5, 13 Hz), 3.35-3.46 (1H, m), 3.60-
3.75 (1H, m), 4.28 (1H, brd, J ) 4 Hz), 4.67-4.75 (1H, m),
5.33 (1H, s), 7.15-7.27 (3H, m), 7.44-7.49 (2H, m); 13C NMR
(67.5 MHz) (CDCl3) δ 15.08 (q), 20.49 (q), 40.73 (t), 63.80 (t),
78.38 (d), 79.26 (d), 84.76 (d), 126.18 (d), 128.89 (d), 130.71
(d), 131.95 (s), 159.02 (s). Anal. Calcd for C14H18O2Se: C,
56.57; H, 6.10. Found: C, 56.42; H, 6.06.
(Z)-(3R*,5R*)-5-ter t-Bu tyl-3-eth oxy-2-((p h en ylselen o)-
m eth ylen e)tetr a h yd r ofu r a n (23b): a yellow oil; IR (film,
1
cm-1) 1640, 1120, 980 (COC); H NMR (400 MHz) (CDCl3) δ
0.91 (9H, s), 1.25 (3H, t, J ) 7 Hz), 1.74-1.76 (1H, m), 2.29-
2.35 (1H, m), 3.60-3.65 (2H, m), 3.97 (1H, dd, J ) 5, 10 Hz),
4.54 (1H, brt, J ) 7 Hz), 5.31 (1H, s), 7.16-7.26 (3H, m), 7.46-
7.48 (2H, brd, J ) 7 Hz); 13C NMR (100 MHz) (CDCl3) δ 15.42
(q), 25.21 (q), 32.69 (s), 33.75 (t), 65.53 (s), 78.85 (d), 81.08 (d),
87.17 (d), 125.96 (d), 128.87 (d), 130.62 (d), 159.82 (s); high-
resolution mass calcd for C17H24O2Se m/ z 340.0942, m/ z
340.0916.
(Z)-(3R*,5R*)-3-Eth oxy-4,4,5-tr im eth yl-2-((p h en ylsele-
n o)m eth ylen e)tetr a h yd r ofu r a n (29): a yellow oil; IR (film,
cm-1) 1640, 1270, 1090 (COC); 1H NMR (270 MHz) (CDCl3) δ
0.85 (3H, s), 0.87 (3H, s), 1.18 (3H, d, J ) 7 Hz), 1.19 (3H, t,
J ) 7 Hz), 3.31-3.42 (1H, m), 3.63 (1H, s), 3.69-3.78 (1H, m),
4.34 (1H, q, J ) 6 Hz), 5.29 (1H, s), 7.14-7.27 (3H, m), 7.43-
7.48 (2H, m); 13C NMR (67.5 MHz) (CDCl3) δ 13.50 (q), 15.03
(q), 18.01 (q), 19.48 (q), 44.31 (s), 64.24 (t), 84.24 (d), 84.32
(d), 86.87 (d), 126.07 (d), 128.89 (d), 130.56 (d), 132.34 (s),
159.46 (s); high-resolution mass calcd for C16H22O2Se m/ z
326.0785, found m/ z 326.0772.
(Z)-(3R*,5S*)-5-ter t-Bu tyl-3-eth oxy-2-(deu ter io(ph en ylse-
len o)m eth ylen e)tetr a h yd r ofu r a n (24): a yellow oil; IR
(film, cm-1) 2300, 1640, 1220 (COC); 1H NMR (400 MHz)
(CDCl3) δ 0.90 (9H, s), 1.21 (3H, t, J ) 7 Hz), 1.87-1.94 (1H,
m), 2.03 (1H, dd, J ) 5, 13 Hz), 3.36-3.40 (1H, m), 3.69-3.73
(1H, m), 4.24 (1H, brd, J ) 5 Hz), 4.34 (1H, dd, J ) 6, 10 Hz),
7.19-7.25 (3H, m), 7.47 (2H, brd, J ) 7 Hz); 13C NMR (100
MHz) (CDCl3) δ 15.14 (q), 25.24 (q), 33.52 (s), 33.96 (t), 63.73
(t), 76.26 (d), 89.43 (d), 126.26 (d), 128.97 (d), 131.00 (d), 132.04
(s), 158.50 (s); high-resolution mass calcd for C17H23DO2Se m/ z
341.1004, found m/ z 341.0987.
(Z)-(3R*,5S*)-5-(p-Br om oph en yl)-3-eth oxy-2-((ph en ylse-
len o)m eth ylen e)tetr a h yd r ofu r a n (25a ): a yellow oil; IR
(film, cm-1) 1640, 1480, 1220, 1080 (COC); 1H NMR (400 MHz)
(CDCl3) δ 1.23 (3H, t, J ) 7 Hz), 1.96-2.03 (1H, m), 2.52 (1H,
dd, J ) 5, 13 Hz), 3.39-3.46 (1H, m), 3.69-3.75 (1H, m), 4.35
(1H, d, J ) 5 Hz), 5.49 (1H, s), 5.54 (1H, dd, J ) 5, 10 Hz),
7.15 (2H, d, J ) 8 Hz), 7.21-7.27 (3H, m), 7.43 (2H, d, J ) 8
Hz), 7.50 (2H, d, J ) 8 Hz); 13C NMR (100 MHz) (CDCl3) δ
15.08 (q), 42.16 (t), 63.89 (t), 78.74 (d), 82.07 (d), 86.84 (d),
121.62 (s), 126.45 (d), 127.18 (d), 129.03 (d), 131.02 (d), 131.52
(Z)-(3R*,5S*)-3-Eth oxy-5-p h en yl-2-((p h en ylth io)m eth -
ylen e)tetr a h yd r ofu r a n (30): a yellow oil; IR (film, cm-1
)
1
1650, 1480, 1090 (COC); H NMR (400 MHz) (CDCl3) δ 1.26
(3H, t, J ) 7 Hz), 2.06-2.13 (1H, m), 2.53 (1H, ddd, J ) 1, 5,
13 Hz), 3.43-3.50 (1H, m), 3.73-3.80 (1H, m), 4.40 (1H, d, J
) 5 Hz), 5.32 (1H, s), 5.61 (1H, dd, J ) 5, 10 Hz), 7.41-7.18
(1H, m), 7.23-7.38 (9H, m); 13C NMR (100 MHz) (CDCl3) δ
15.15 (q), 41.91 (t), 64.00 (t), 78.96 (d), 83.13 (d), 90.63 (d),
125.52 (d), 125.61 (d), 127.73 (d), 127.93 (d), 128.48 (d), 137.22
(s), 140.30 (s), 158.78 (s); high-resolution mass calcd for
C19H20O2S m/ z 312.1184, found m/ z 312.1170.
(Z)-(3R *,5S *)-5-t er t -Bu t yl-3-e t h oxy-2-((p h e n ylt h io)-
m eth ylen e)tetr a h yd r ofu r a n (31): a yellow oil; IR (film,
cm-1) 1640, 1480, 1090 (COC); 1H NMR (400 MHz) (CDCl3) δ
0.90 (9H, s), 1.22 (3H, t, J ) 7 Hz), 1.90-1.99 (1H, m), 2.01-
2.04 (1H, m), 3.36-3.42 (1H, m), 3.67-3.73 (1H, m), 4.25 (1H,
brd, J ) 5 Hz), 4.33-4.37 (1H, m), 5.15 (1H, s), 7.13 (1H, brt,
J ) 7 Hz), 7.25 (2H, brt, J ) 7 Hz), 7.32 (2H, brd, J ) 7 Hz);
13C NMR (100 MHz) (CDCl3) δ 15.11 (q), 25.19 (q), 33.48 (s),
33.60 (t), 63.71 (t), 79.27 (d), 89.31 (d), 89.67 (d), 125.30 (d),
127.62 (d), 128.68 (d), 137.57 (s), 159.21 (s). Anal. Calcd for
C17H24O2S: C, 69.82; H, 8.27. Found: C, 69.58; H, 8.31.
p-Nitr oben zoyla tion of Alk yn yl Alcoh ol 16. 4-(Dimeth-
ylamino)pyridine (10 mg, 0.08 mmol) was added to a CH2Cl2
(3 mL) solution of (1R*,3R*)-3-ethoxy-2,2-pentamethylene-1-
phenyl-5-(phenylseleno)pent-4-yn-1-ol (16a ) (0.10 g, 0.23 mmol)
and Et3N (47 mg, 0.47 mmol). The mixture was stirred for 2
h. The mixture was poured into water (100 mL). The organic
(d), 139.47 (s), 157.83 (s); high-resolution mass calcd for C19H19
-
BrO2Se m/ z 437.9734, found m/ z 437.9714.
(Z)-(3R*,5R*)-5-(p-Br om oph en yl)-3-eth oxy-2-((ph en ylse-
len o)m eth ylen e)tetr a h yd r ofu r a n (25b): a yellow oil; IR
(film, cm-1) 1650, 1480, 1230, 1105, 1005 (COC); 1H NMR (400
MHz) (CDCl3) δ 1.20 (3H, t, J ) 7 Hz), 1.98-2.05 (1H, m),
2.73-2.80 (1H, m), 3.51-3.57 (1H, m), 3.58-3.64 (1H, m), 4.57
(1H, brt, J ) 7 Hz), 5.29 (1H, brt, J ) 7 Hz), 5.50 (1H, s),
7.18-7.28 (5H, m), 7.44 (2H, d, J ) 8 Hz), 7.50 (2H, d, J ) 8
Hz); 13C NMR (100 MHz) (CDCl3) δ 15.26 (q), 40.28 (t), 65.04
(t), 78.46 (d), 80.86 (d), 84.35 (d), 121.70 (s), 126.34 (d), 127.49
(d), 129.03 (d), 130.86 (d), 131.46 (d), 131.90 (s), 139.86 (s),
158.80 (s); high-resolution mass calcd for C19H19BrO2Se m/ z
437.9734, found m/ z 437.9750.

8206 J . Org. Chem., Vol. 61, No. 23, 1996
Yoshimatsu et al.
layer was separated, and the aqueous layer was extracted with
ether. The organic layer and the extracts were combined and
dried over MgSO4. The solvent was removed under reduced
pressure. The residue was purified by preparative TLC on
silica gel eluting with AcOEt-n-hexane (1:10). (1R*,3R*)-3-
Ethoxy-1-((p-nitrobenzoyl)oxy)-2,2-pentamethylene-1-phenyl-
5-(phenylseleno)pent-4-yne (16′) (0.13 g, quant) was obtained
as colorless prisms: mp 119-120 °C; IR (KBr, cm-1) 2150
(acetylene), 1730 (CO), 1530, 1280 (NO2); 1H NMR (400 MHz)
(CDCl3) δ 1.20 (3H, t, J ) 7 Hz), 1.22-1.27 (1H, m), 1.52-
1.54 (6H, m), 1.72 (1H, brs), 1.82 (1H, brs), 2.29 (1H, brs),
3.38-3.42 (1H, m), 3.86-3.90 (1H, m), 4.52 (1H, brs), 6.40 (1H,
brs), 7.20-7.32 (8H, m), 7.39 (2H, brd, J ) 7 Hz), 8.11 (2H, d,
J ) 9 Hz), 8.24 (2H, brd, J ) 9 Hz); 13C NMR (100 MHz)
(CDCl3) δ 15.05 (q), 21.34 (t), 25.49 (t), 28.02 (t), 28.53 (t), 44.82
(s), 60.39 (t), 65.01 (t), 66.13 (s), 71.51 (d), 78.57 (d), 102.49
(s), 123.37 (d), 126.92 (d), 127.83 (d), 127.91 (d), 128.18 (d),
128.40 (d), 128.73 (s), 129.50 (d), 131.02 (d), 135.88 (s), 137.69
(s), 150.22 (s), 163.50 (s). Anal. Calcd for C31H31NO5Se: C,
64.58; H, 5.42; N, 2.43. Found: C, 64.45; H, 5.46; N, 2.44.
(3S*,5R*)-2,2-Dim eth yl-5-eth oxy-7-(p h en ylselen o)h ep t-
6-yn -3-yl Tetr a h yd r op yr a n yl Eth er (36). The THP ether
36 was prepared from the corresponding alcohol 13a by the
general procedure22 using pyridinium p-toluenesulfonate (PPTS)
quantitatively. The ether 36 was obtained as a diastereoiso-
meric mixture. The isomer ratio (1:1) was determined by the
intensities of the t-Bu groups in the 1H NMR spectrum; IR
was purified by distillation. 3-Deuterio-3,3-diethoxy-1-propyne
(39) (1.43 g, 59.0%) (bp 75-80 °C/100 mmHg) was obtained
1
as a colorless oil: IR (film, cm-1) 3260, 2120 (acetylene); H
NMR (270 MHz) (CDCl3) δ 1.18 (6H, t, J ) 8 Hz), 2.50 (1H, s),
3.41-3.75 (4H, m). An Et2O (5 mL) solution of propyne 39
(0.65 g, 5.0 mmol) was added dropwise to the EtMgBr (10
mmol) prepared as described above. The reaction mixture was
refluxed for 30 min. A THF (10 mL) solution of PhSeBr
(prepared from (PhSe)2 (0.78 g, 2.5 mmol) and Br2 (0.40 g, 2.5
mmol)) was added dropwise to the mixture over 30 min at 0
°C. The whole was stirred for 10 min and poured into water
(100 mL). The organic layer was separated, and the aqueous
layer was extracted with ether. The combined organic layer
was dried over MgSO4. The solvent was removed under
reduced pressure. The residue was purified by column chro-
matography on silica gel eluting with AcOEt-n-hexane (1:20).
3-Deuterio-3,3-diethoxy-1-(phenylseleno)-1-propyne (40) (0.43
g, 30%) was obtained as a pale yellow oil: IR (film, cm-1) 2150
(acetylene); 1H NMR (270 MHz) (CDCl3) δ 1.25 (6H, dt, J ) 2,
7 Hz), 3.54-3.83 (4H, m), 7.23-7.35 (3H, m), 7.50-7.55 (2H,
m); high-resolution mass calcd for C13H15DO2Se m/z 285.0378,
found m/ z 285.0377. The following experiments were per-
formed by the same procedures as described above.
5-Deu ter io-2,2-dim eth yl-5-eth oxy-7-(ph en ylselen o)h ept-
6-yn -3-on e (41): a yellow oil; IR (film, cm-1) 2150 (acetylene),
1720 (CO); 1H NMR (400 MHz) (CDCl3) δ 1.13 (9H, s), 1.19
(3H, t, J ) 7 Hz), 2.79 (1H, d, J ) 17 Hz), 3.08 (1H, d, J ) 17
Hz), 3.44-3.50 (1H, m), 3.76-3.84 (1H, m), 7.24-7.37 (3H,
m), 7.48-7.56 (2H, m); 13C NMR (67.5 MHz) (CDCl3) δ 14.95
(q), 25.84 (q), 42.86 (t), 44.05 (s), 64.75 (t), 65.12 (s), 102.62
(s), 127.02 (d), 128.47 (s), 128.95 (d), 129.40 (d), 211.55 (s);
high-resolution mass calcd for C17H21DO2Se m/z 339.0845,
found m/ z 339.0844.
1
(film, cm-1) 2200 (acetylene); H NMR (270 MHz) (CDCl3) δ
0.88 (s), 0.93 (s), 1.23 (t, J ) 7 Hz), 1.25 (t, J ) 7 Hz), 1.43-
1.48 (m), 1.90-1.97 (m), 3.33-3.44 (m), 3.51 (q, J ) 7 Hz),
3.82-3.92 (m), 4.27 (dd, J ) 10, 6 Hz), 4.40 (brs), 4.64 (brs),
4.73 (dd, J ) 10, 5 Hz), 7.23-7.32 (m), 7.51-7.55 (m); 13C NMR
(67.5 MHz) (CDCl3) δ 15.06 (q), 15.15 (q), 20.56 (t), 21.15 (t),
25.25 (t), 25.35 (t), 25.99 (q), 26.38 (q), 31.03 (t), 31.49 (t), 34.88
(s), 35.65 (s), 38.06 (t), 38.29 (t), 60.19 (s), 63.69 (t), 64.20 (t),
64.53 (t), 66.29 (s), 69.23 (d), 69.57 (d), 81.79 (d), 85.25 (d),
99.15 (d), 102.71 (d), 102.95 (s), 104.41 (s), 126.76 (d), 127.04
(d), 128.67 (d), 129.02 (d), 129.13 (d), 129.26 (d), 129.37 (d).
Anal. Calcd for C22H32O3Se: C, 61.93; H, 7.62. Found: C,
61.96; H, 7.50.
(3S*,5R*)-5-Deu ter io-2,2-dim eth yl-5-eth oxy-7-(ph en ylse-
len o)h ep t-6-yn -3-ol (42): a colorless oil; IR (film, cm-1
)
3650-3200 (OH), 2180 (acetylene); 1H NMR (270 MHz)
(CDCl3) δ 0.91 (9H, s), 1.25 (3H, t, J ) 7 Hz), 1.82-2.00 (2H,
m), 3.10 (1H, brs), 3.48-3.54 (2H, m), 3.87-3.93 (1H, m), 7.25-
7.34 (3H, m), 7.49-7.53 (2H, m); 13C NMR (67.5 MHz) (CDCl3)
δ 15.06 (q), 25.55 (q), 34.66 (s), 37.65 (t), 64.75 (t), 65.93 (s),
70.66 (sx3), 78.52 (d), 102.41 (s), 127.13 (d), 128.30 (s), 128.98
(d), 129.48 (d); high-resolution mass calcd for C17H23DO2Se m/z
341.1004, found m/ z 341.1009.
A P r ep a r a tion of 3-Deu ter io-3,3-d ieth oxy-1-(p h en ylse-
len o)-1-p r op yn e (40). An Et2O (18 mL) solution of (trimeth-
ylsilyl)acetylene (2.80 g, 28.1 mmol) was added dropwise to
EtMgBr (prepared from Mg (0.680 g, 28.1 mmol) and EtBr
(3.06 g, 28.1 mmol) in Et2O (20 mL)) at room temperature.
The mixture was refluxed for 30 min. An Et2O solution (10
(Z)-(3R *,5S *)-5-t er t -B u t y l-3-d e u t e r io -3-e t h o x y -2-
((p h en ylselen o)m eth ylen e)tetr a h yd r ofu r a n (43): a yel-
low oil; IR (film, cm-1) 1640, 1240, 1070 (COC); 1H NMR (400
MHz) (CDCl3) δ 0.90 (9H, s), 1.21 (3H, t, J ) 7 Hz), 1.90 (1H,
dd, J ) 10, 13 Hz), 2.02 (1H, dd, J ) 6, 13 Hz), 3.33-3.44
(1H, m), 3.65-3.76 (1H, m), 4.34 (1H, dd, J ) 6, 10 Hz), 5.31
(1H, s), 7.15-7.27 (3H, m), 7.46-7.49 (2H, m); 13C NMR (67.5
MHz) (CDCl3) δ 15.10 (q), 25.20 (q), 33.49 (s), 33.82 (t), 63.65
(t), 79.22 (sx3), 85.16 (d), 89.40 (d), 126.21 (d), 128.93 (d),
130.98 (d), 132.04 (s), 158.54 (s); high-resolution mass calcd
for C17H23DO2Se m/z 341.1004, found m/ z 341.1008.
18
mL) of CD(OEt)3 (2.80 g, 18.8 mmol) was added dropwise to
the mixture at room temperature. The mixture was refluxed
for 1 h and then poured into water (150 mL). The organic
layer was separated, and the aqueous layer was extracted with
Et2O. The organic layer and the extracts were combined and
dried over MgSO4. The solvent was removed under reduced
pressure. The mixture was not purified at this point, and the
next desilylation was performed. Bu4NF (7.30 g, 28.1 mmol)
was added to an EtOH (20 mL)-H2O (10 mL) solution of the
mixture at 0 °C. The reaction mixture was stirred for 1 h and
poured into water (150 mL). The organic layer was separated,
and the aqueous layer was extracted with Et2O. The organic
layer and the extracts were combined and dried over MgSO4.
The solvent was removed under reduced pressure. The residue
Su p p or tin g In for m a tion Ava ila ble: NMR characteriza-
tion data of all compounds complete with peak assignments
(8 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.
(22) Miyashita, M.; Yoshikoshi, A.; Grieco, P. A. J . Org. Chem. 1977,
42, 3772.
J O961071C