1,2-Migration of 2′-oxoalkyl group and concomitant synthesis of 2-C-branched O-, S-glycosides and glycosyl azides via 1,2-cyclopropanated sugars

Article abstract of DOI:10.1021/jo0502854

Treatment of 2′-oxoalkyl 2-O-Ms(Ts)-α-C-mannosides (4, 5, and 6) with base resulted in 1,2-cyclopropanation via an intramolecular S _N2 reaction due to their 1,2-trans-diaxial configurations. The 1,2-cyclopropanated sugars (10 and 13) were react

Full text of DOI:10.1021/jo0502854

1,2-Migration of 2′-Oxoalkyl Group and Concomitant Synthesis of
2-C-Branched O-, S-Glycosides and Glycosyl Azides via
1,2-Cyclopropanated Sugars
Huawu Shao, Sanchai Ekthawatchai, Chien-Sheng Chen,† Shih-Hsiung Wu,† and Wei Zou*
Institute for Biological Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa,
Ontario K1A 0R6, Canada, and Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
wei.zou@nrc-cnrc.gc.ca
Received February 14, 2005
Treatment of 2′-oxoalkyl 2-O-Ms(Ts)-R-C-mannosides (4, 5, and 6) with base resulted in 1,2-
cyclopropanation via an intramolecular SN2 reaction due to their 1,2-trans-diaxial configurations.
The 1,2-cyclopropanated sugars (10 and 13) were reacted with various alcohols, thiols, and sodium
azide to produce 2-C-branched O- and S-glycosides and glycosyl azides (11, 14-28) in good to
excellent yields. In contrast, 1,2-cis 2′-oxoalkyl 2-O-Ms(Ts)-R-C-glucoside 9 formed an acyclic
conjugated aldehyde (31) under basic conditions, which occurred by 1′-enolation followed by
â-elimination. An intramolecular Michael addition from 31 produced 2-O-Ms-â-C-glucoside 30 as
a major product. However, due to the electron-withdrawing effect exerted by 2-O-Ms compound 31
also undergoes a C2 epimerization to form 32. Thereafter, the intramolecular Michael addition led
to the formation of both 1,2-trans 2′-oxoalkyl 2-O-Ms-R-C-mannoside 4 and its â-anomer (33).
Because â-elimination/Michael addition and C2 epimerization are reversible reactions, equilibriums
among 9, 31, 30, 32, 33, and 4 were established, which included the transformation of 1,2-cis
C-glucoside 9 into 1,2-trans C-mannoside 4. The subsequent 1,2-cyclopropanation of 4 was an
irreversible reaction yielding 1,2-cyclopropanated 10 and further conversion to 1,2-migration
products (11 and 12).
Introduction
2-selenoglycosides through their respective 1,2-episulfo-
nium2 and 1,2-episelenonium3 intermediates. These in-
termediates are formed by an intramolecular displace-
ment of a leaving group at the 2-position by the
nucleophilic sulfur or selenium atom at C1. 1,2-Migration
via an aziridine intermediate has also been observed.
Danishefsky et al.4 first reported such 1,2-migration
Because of neighboring group participation the 2-posi-
tion of sugars plays a critical role in the chemical
reactivity and stereoselectivity at the anomeric center.1
2,1-Migration in glycosylation is rare because the ano-
meric carbon is generally more electrophilic due to the
endo-oxonium stabilization, but 1,2-migrations do occur
under certain conditions. For example, it is well-known
that thioglycosides and selenoglycosides may undergo
rearrangement to give alkylated 2-thioglycosides and
(2) (a) Auzanneau, F.-I.; Bundle, D. R. Carbohydr. Res. 1991, 212,
13-24. (b) Pozsgay, V. Carbohydr. Res. 1992, 235, 295-302. (c)
Johnston, B. D.; Pinto, B. M. J. Org. Chem. 2000, 65, 4607-4617. (d)
Yu, B.; Yang, Z. Tetrahedron Lett. 2000, 41, 2961-2964. (e) Yang, Z.;
Yu, B. Carbohydr. Res. 2001, 333, 105-114. (f) Yu, B.; Yang, Z. Org.
Lett. 2001, 3, 377-379.
(3) (a) Jaurand, G.; Beau, J.-M.; Sina, P. J. Chem. Soc,. Chem.
Commun. 1981, 572-573. (b) Kaye, A.; Neidle, S.; Reese, C. B.
Tetrahedron Lett. 1988, 29, 2711-2714. (c) Perez, M.; Beau, J.-M.
Tetrahedron Lett. 1989, 30, 75-78. (d) Roush, W. R.; Sebesta, D. P.;
James, R. A. Tetrahedron 1997, 53, 8837-8852.
(4) (a) Griffith, D. A.; Danishefsky, S. J. J. Am. Chem. Soc. 1990,
112, 5811-5819. (b) Griffith, D. A.; Danishefsky, S. J. J. Am. Chem.
Soc. 1991, 113, 5863-5864. (c) Danishefsky, S. J.; Koseki, K.; Griffith,
D. A.; Gervay, J.; Peterson, J. M.; McDonald, F. E.; Oriyama, T. J.
Am. Chem. Soc. 1992, 114, 8331-8333.
* Address correspondence to this author at the National Research
Council of Canada. Phone: 1-(613)-991-0855. Fax: 1-(613)-952-9092.
† Institute of Biological Chemistry, Academia Sinica.
(1) (a) Carbohydrates in Chemistry and Biology; Ernst, B., Hart, G.
W., Sinay¨, P., Eds.; Wiley-VCH: Weiheim, Germany, 2000;, Vol. 1. (b)
Preparative Carbohydrate Chemistry; Hanessian, S., Ed.; Marcel
Dekker: New York, 1996. (c) Oscarsson, S. Topics in Current Chem-
istry: Glycoscience; Driguuez, H., Thiem, J., Eds.; Springer: Berlin,
Germany, 1997; Vol. 186. (d) Lemieux, R. U. Adv. Carbohydr. Chem.
1954, 9, 1-57. (e) Lemieux, R. U.; Brice, C.; Huber, G. Can. J. Chem.
1955, 33, 134-147.
10.1021/jo0502854 CCC: $30.25 © 2005 American Chemical Society
Published on Web 05/07/2005
4726
J. Org. Chem. 2005, 70, 4726-4734

2-C-Branched O-, S-Glycosides and Glycosyl Azides
SCHEME 1. Synthesis of 2′-Carbonylalkyl 2-O-Ms(Ts)-C-glycosides
when a 2-iodo-1-N-sulfonamide sugar was treated with
lithium ethanethiolate and yielded trans-2-N-sulfon-
amide-â-thioglycoside. Recently, Finney et al.5 found that
triazolines obtained from glycal and azides produced
aziridine intermediates by photolysis, which following a
subsequent SN2 reaction at the anomeric carbon produced
2-aminoglycosides. In addition to 1,2-migrations via
three-membered heterocyclic intermediates, we found
that 1,2-cyclopropanated sugar intermediates were formed
by base treatment of 2′-oxoalkyl 2-O-Ms(Ts)-R-C-man-
nopyranoside prior to their nucleophilic ring opening and
the concomitant formation of the 2-C-branched glyco-
sides.6
However, the above study on the 1,2-migration of the
2′-oxoalkyl group was limited to 2′-oxoalkyl 2-O-Ms(Ts)-
R-mannosides, which have 1,2-trans configurations. Be-
cause 2′-oxoalkyl C-glycosides can also undergo a â-e-
limination under basic conditions to form an acyclic R,â-
unsaturated aldehyde (ketone),7 this â-elimination will
compete with 1,2-cyclopropanation after the initial 1′-
enolation. Furthermore, unlike the 1,2-cyclopropanated
sugar from 2′-aldehydo 2-O-Ms-R-C-mannosides that
reacted with various nucleophiles (alcohols, thiols, and
sodium azide) the one derived from 2′-ketonyl 2-O-Ms-
R-C-mannoside failed to give a 2-C-branched O-glycoside
and a glycosyl azide and only reacted with thiols to
produce 2-C-acetylmethyl-2-deoxy-â-thioglucosides. In
this report, we describe the successful preparation of
additional 2-C-branched glycosides including those 2-C-
acetylmethyl-2-deoxy-â-O-glycosides and a glycosyl azide
by a modified procedure. The mechanism controlling the
competitive 1,2-cyclopropanation and â-elimination pro-
cess is also discussed, using 1,2-cis 2′-oxoalkyl 2-O-Ms-
R-C-glucoside as a substrate.
Results and Discussion
Synthesis of 2′-Oxoalkyl 2-O-Ms(Ts)-C-glycosides
(4, 5, 6, and 9). Allyl C-mannoside 1 and C-glucoside 7
previously prepared were used as the starting materials.8
Conventional removal of 2-O-Ac was followed by mesy-
lation or tosylation as shown in Scheme 1 to afford 2, 3,
and 8, respectively, in good yields. These allyl C-glyco-
sides were then subjected to ozonolysis to give respective
2′-aldehydo C-glycosides (4, 5, and 9). 2′-Ketonyl C-
mannoside 6 was initially prepared from aldehyde 5 in
two steps by a Grignard reaction (MeMgBr) followed by
PCC oxidation of resultant 2′-alcohol. However, 6 can be
more efficiently obtained from 3 by oxidizing the olefin
double bond, using Hg(OAc)2 and Jones reagent (see
Scheme 1).9
1,2-Cyclopropanated Sugars and 2-C-Branched
Glycosides. 1,2-Cyclopropaned sugars are often pro-
duced from glycals by treatment with diazo esters,
Simmons-Smith reagents, or dihalocarbenes.10 Four
possible diastereomers are formed depending on the
reaction conditions and the protecting groups. The ad-
dition to the alkene (cyclopropanation) is stereoselctive
in most cases; however, the stereochemistry of the
bridged carbon is less certain, resulting in a mixture of
cis and trans diastereomers. Ring opening of the 1,2-
cyclopropaned sugars by solvolysis in the presence of
mercury,11 strong acid,12 halonium,13 and platinum14 gave
(8) Zou, W.; Wang, Z.; Lacroix, E.; Wu, S.-H.; Jennings, H. Carbo-
hydr. Res. 2001, 334, 223-231.
(9) (a) Rogers, H. R.; McDermott, J. X.; Whitesides, G. M. J. Org.
Chem. 1975, 40, 3577-3580. (b) Bowers, A.; Halsall, T. G.; Jones, E.
R. H.; Lemin, A. J. J. Chem. Soc. 1953, 2555-2560.
(10) Cousins, G. S.; Hoberg, J. O. Chem. Soc. Rev. 2000, 29, 165-
174.
(11) Scott, R. W.; Heathcock, C. H. Carbohydr. Res. 1996, 291, 205-
208.
(12) (a) Kim, C.; Hoang, R.; Theodorakis, E. A. Org. Lett. 1999, 1,
1295-1297. (b) Hoberg, J. O.; Claffey, D. J. Tetrahedron Lett. 1996,
37, 2533-2536.
(13) (a) Ramana, C. V.; Murali, R.; Nagarajan, M. J. Org. Chem.
1997, 62, 7694-7703. (b) Ramana, C. V.; Nagarajan, M. Synlett 1997,
763-764. (c) Bertinato, P.; Sorensen, E. J.; Meng, D.; Danishefsky, S.
J. J. Org. Chem. 1996, 61, 8000-8001.
(14) (a) Beyer, J.; Skaanderup, P. R.; Madsen, R. J. Am. Chem. Soc.
2000, 122, 9575-9583. (b) Beyer, J.; Madsen, R. J. Am. Chem. Soc.
1998, 120, 12137-12138.
(5) Dahl, R. S.; Finney, N. S. J. Am. Chem. Soc. 2004, 126, 8356-
8357.
(6) Shao, H.; Ekthawatchai, S.; Wu, S.-H.; Zou, W. Org. Lett. 2004,
6, 3497-3499.
(7) (a) Shao, H.; Wang, Z.; Laroix, E.; Wu, S.-H.; Jennings, H.; Zou,
W. J. Am. Chem. Soc. 2002, 124, 2130-2131. (b) Wang, Z.; Shao, H.;
Laroix, E.; Wu, S.-H.; Jennings, H.; Zou, W. J. Org. Chem. 2003, 68,
8097-8105.
J. Org. Chem, Vol. 70, No. 12, 2005 4727

Shao et al.
SCHEME 2. 1,2-Migration of the Formylmethyl
Group
often have a large coupling constant, e.g., JH1,H2 ) 7.2
Hz as observed.
We proposed a mechanism in which the ring opening
of cyclopropanated 10 to 2-C-formylmethyl-2-deoxy-â-
glycoside 11 resulted from a SN2 reaction at the anomeric
center similar to those previously reported by Danishef-
sky et al.4 and by Finney et al.5 Although there was no
R-anomer isolated, it was still possible that both 11 and
the bicyclic 12 were formed through a zwitterionic
intermediate18 derived by ring-opening enolation. An
intramolecular reaction between the enolate and oxycar-
bonium gave 12 while the intermolecular addition at the
anomeric carbon afforded 11. This mechanism was
consistent with the fact that we were able to obtain 11
as the only major product without the bicyclic 12 when
4 and 5 were treated with TEA in methanol or potassium
carbonate in acetonitrile (see Scheme 2), because the
ring-opening enolation becomes less likely in the presence
of weaker bases. On the basis of these observations we
reasoned that the chemoselectivity of the reaction might
depend on (1) the stability of the 1,2-cyclopropanated
sugars and (2) the relative basicity and nucleophilicity
of the reagent. A stable 1,2-cyclopropanated sugar such
as 13 and a better nucleophile should favor the SN2
substitution at the anomeric carbon over the ring-opening
enolation, leading to 1,2-migration of the 2′-oxoalkyl
group.
As predicted, when compounds 4 and 5 were treated
with various nucleophiles (alcohol, thiols, and sodium
azide) under TEA or K2CO3, 1,2-migration and concomi-
tant glycosylation provided 2-C-branched glycosides (14
to 22) in good to excellent yields (see Table 1), and no
rearrangement product 12 was isolated. The dependence
of chemoselectivity on the nuleophilicity was evidenced
further by the fact that we were able to obtain respective
O- and S-glycosides (15, 19-21) and glycosyl azide (22)
in methanol (entries 3 and 7-10 in Table 1) when better
nucleophiles such as allyl alcohol, thiols, and azide were
used. Because 13 is a more stable 1,2-cyclopropanated
sugar than 10 and methoxide is a poor nucleophile,
treatment of 13 with K2CO3 in methanol at room tem-
perature resulted in neither methoxide addition at the
anomeric carbon nor rearrangement. In contrast, both
2′-ketone 6 and 13 reacted with thiols under K2CO3/
MeOH at room temperature to form 2-C-acetylmethyl-
2-deoxy-â-thioglycosides (23 and 24) in excellent yields
(see entries 1 and 2 in Table 2). Indeed, we were also
able to obtain 23 and 24 by treatment of 13 and the
respective thiols in methanol without additional base.
This result suggests that the 1,2-migration of acetyl-
methyl group might occur in alcohols at higher temper-
ature to produce 2-C-branched O-glycosides as a result
of the destabilization of 1,2-cyclopropanated 13 and
increased nucleophilicity of alcohols. To our satisfaction,
treatment of 13 with various alcohols and sodium azide
produced 2-C-acetylmethyl-2-deoxy-â-O-glycosides (25-
2-C-branched sugars with R-glycosides as major products,
regardless of the configuration of the substrates, due to
the involvement of an oxocarbonium-like intermediate
and the anomeric effect. A two-step ring opening of
cyclopropanecarboxylate sugars mediated by NIS favors
1,2-trans 2-C-branched glycosides, likely due to the
neighboring group participation.15
Treatment of 2′-oxoalkyl 2-O-Ts(Ms)-R-C-mannosides
(4 and 5) with sodium methoxide in methanol produced
2-C-branched methyl â-glycoside 11 and a bicyclic deriva-
tive 12 via 1,2-cyclopropanated sugar 10 (see Scheme 2).16
The â-configuration of 11 was unambiguously determined
by the observation of nOe between H1 and H3 and the
large coupling constant of J1,2 ) 8.8 Hz. Compound 10,
an intermediate, was not stable and decomposed during
the chromatographic purification but was detected as a
major product by the TLC analysis when 4 and 5 were
treated with base (K2CO3 and t-BuOK) in DMF. However,
when 2′-ketone 6 was treated with K2CO3 in methanol,
1,2-cyclopropanated 13 was isolated as a major product
(>80% yield) (see Scheme 2), which surprisingly did not
transform to 2-C-branched methyl â-glucoside as ex-
pected. Compound 13 was a pure diasteroisomer with a
trans configuration at bridged C1′ as indicated by the
nOe between H1′ and H3 and supported by the coupling
constants (JH1′,H1 ) 1.6 Hz, JH1′,H2 ) 5.6 Hz, and JH1,H2
)
7.2 Hz). Those small coupling constants (JH1′,H1 and
JH1′,H2) are consistent with the trans stereochemistry
reported in the literature on the respective 1,2-cyclo-
propanated sugar esters,12,17 while the cis configurations
(17) Proton-proton coupling constants in a cyclopropane system:
J ) 0-6 Hz for a trans stereochemistry and J ) 8-10 Hz for a cis
stereochemistry. See: (a) Kawabata, N.; Nakagawa, T.; Nakao, T.;
Yamashita, S. J. Org. Chem. 1977, 42, 3031-3035. (b) Wiberg, K. B.;
Barth, D. E.; Schertler, P. H. J. Org. Chem. 1973, 38, 378-381. (c)
Williamson, K. L.; Lanford, C. A.; Nicholson, C. R. J. Am. Chem. Soc.
1964, 86, 762-765.
(15) Sridhar, P. R.; Ashalu, K. C.; Chandrasekaran, S. Org. Lett.
2004, 6, 1777-1779.
(16) For intramolecular SN2 reactions to form other cyclopropanated
sugars, see: (a) Fraser-Reid, B.; Holder, N. L.; Hicks, D. R.; Walker,
D. L. Can. J. Chem. 1977, 55, 3978-3985. (b) Kawana, M.; Kuzuhara,
H. Synthesis 1995, 544-552.
(18) Biggs, T. N.; Swenton, J. S. J. Org. Chem. 1992, 57, 5568-
5573.
4728 J. Org. Chem., Vol. 70, No. 12, 2005

2-C-Branched O-, S-Glycosides and Glycosyl Azides
TABLE 1. Synthesis of 2-C-Formylmethyl-2-deoxy-â-O- and S-glucosides and Glucosyl Azide
27) and glycosyl azide (28) in excellent yields (see entries
3-6 in Table 2). These experiments demonstrated that
the ring opening of a 1,2-cyclopropanated sugar can be
achieved by solvolysis without additional catalyst.11-14
Unlike the catalytic solvolysis of 1,2-cyclopropanated
sugars including 1,2-cyclopropanated esters which gave
a mixture of anomers through an oxocarbonium inter-
mediate, the formation of only the â-anomers suggests
that the solvolysis of 1,2-cyclopropanated sugar ketones
and aldehydes reported here likely followed an SN2
mechanism.19 In the absence of a good nucleophile the
destabilized 1,2-cyclopropane 13 was forced to a thermal
rearrangement to give bicyclic 29 (see entry 7 in Table
2).
Because 2-C-branched sugars can mimic N-acyl-
sugars20 and are used as inhibitors of lipid A biosynthe-
sis21 by interacting with the N-acylase (LpxD),22 these
compounds could also have potential to be modified as
inhibitors.
(20) The glycoprocessing enzymes may promiscuously incorporate
the 2-C-acetylmethyl-2-deoxy sugars into the biosynthetic pathway to
replace 2-N-acetylsugars. See: Hang, H. C.; Bertozzi, C. R. J. Am.
Chem. Soc. 2001, 123, 1242-1243.
(21) Li, X.; Uchiyama, T.; Raetz, C. R. H.; Hindgaul, O. Org. Lett.
2003, 5, 539-541.
(19) 1,2-Cyclopropanated sugar esters were stable under these
neutral solvolysis conditions, but decomposed under basic conditions.
J. Org. Chem, Vol. 70, No. 12, 2005 4729

Shao et al.
TABLE 2. Synthesis of 2-C-Acetylmethyl-2-deoxy-â-O- and S-glucosides and Glucosyl Azide
SCHEME 3. Epimerization and 1,2-Migration
1,2-Migration and Epimerization. Besides the SN2
displacement at C2 to form 1,2-cyclopropanated sugars
following C1′-enolation under basic conditions, â-elimina-
tion leading to an acyclic R,â-conjugated aldehyde (ke-
tone) may also occur.8 Due to the 1,2-trans configurations
in R-C-mannosides (4, 5, and 6) 1,2-cyclopropanation was
favored over â-elimination. We expected when R-C-
glucoside 9, which has the 1,2-cis configuration, was used,
that â-elimination would be dominant leading to ano-
meric epimerization or an SN2 displacement of 2-OMs by
5-OH to form a C-glycofuranoside.23 Unexpectedly, we
obtained 11 and 12 from 9 as major products in 50-70%
yield when treated with NaOMe/MeOH at room temper-
ature overnight (see Scheme 3). These were the same
products obtained from the NaOMe/MeOH treatment of
R-mannosides 4 and 5 (see Scheme 2). By monitoring the
reaction on TLC we observed that a major intermediate
was formed within 4 h at room temperature prior to its
further transformation to 11 and 12. Thus, this inter-
mediate was isolated in 55-60% yield and characterized
to be 2′-formylmethyl 2-O-Ms-â-C-glucoside 30, an ano-
meric epimer of 9. This result suggests that the â-elim-
ination proceeded favorably in 9, but not 1,2-cyclopropa-
nation due to the lack of required 1,2-trans-diaxial
configuration.
The transformation of 30 to 11 and 12 was intriguing
but could be explained through a mechanism illustrated
in Figure 1. â-Elimination from 9 gave an acyclic conju-
gate 31, which quickly underwent a hetero-Michael
addition to form more stable â-anomer 30. However,
compound 30 can be converted to 31 by â-elimination,
and be further converted to 32 by C2 epimerization
through another equilibrium. Similar epimerizations at
C2 have previously been observed in Horner-Emmons
reaction on 2-acetamidosugar lactols and in 2-bromo
sugars under basic conditions.24 Meanwhile, an intra-
(22) Jackman, J. E.; Fierke, C. A.; Tumey, L. N.; Pirrung, M.;
Uchiyama, T.; Tahir, S. H.; Hindsgaul, O.; Raetz, C. R. H. J. Biol.
Chem. 2000, 275, 11002-11009.
(23) For examples of such intramolecular SN2 reactions. See: (a)
Sanjayan, G. J.; Stewart, A.; Hachisu, S.; Gonzalez, R.; Watterson, M.
P.; Fleet, G. Tetrahedron Lett. 2003, 44, 5847-5851. (b) Watterson,
M. P.; Edwards, A. A.; Leach, J. A.; Smith, M. D.; Ichihara, O.; Fleet,
G. Tetrahedron Lett. 2003, 44, 5853-5857. (c) Harvey, J. E.; Raw, S.
A.; Taylor, J. K. Org. Lett. 2004, 6, 2611-2614.
(24) (a) Allevi, P.; Ciuffreda, P.; Colombo, D.; Monti, D.; Speranza,
G.; Manitto, P. J. Chem. Soc., Perkin Trans. 1 1989, 1281-1283. (b)
Werner, R. M.; Williams, L. M.; Davis, J. T. Tetrahedron Lett. 1998,
39, 9135-9138. (c) Marzabadi, C. H.; Spilling, C. D. J. Org. Chem.
1993, 58, 3761-3766. (d) Wen, X.; Hultin, P. Tetrahedron Lett. 2004,
45, 1773-1775.
4730 J. Org. Chem., Vol. 70, No. 12, 2005

2-C-Branched O-, S-Glycosides and Glycosyl Azides
concentrated to a residue. To a solution of the above residue
and Et3N (0.39 mL) in CH2Cl2 (10 mL) was added at 0 °C a
solution of MsCl (0.239 g, 2.09 mmol) in CH2Cl2 (6 mL). The
mixture was stirred overnight at room temperature, then
methanol (1.5 mL) was added to destroy excess MsCl. Usual
workup and chromatography (hexane/EtOAc 3:1) gave 2 (0.673
g, 83%) as a syrup: [R]D +8.0 (c 0.25, CHCl3); 1H NMR (CDCl3)
δH 2.32 (m, 1H, CHHCHdCH2), 2.45 (m, 1H, CHHCHdCH2),
3.02 (s, 3H, SO2CH3), 3.67-3.77 (m, 3H, H-5, H-6, H-6′), 3.80
(dd, 1H, H-4, J ) 8.4, 8.4 Hz), 3.88 (dd, 1H, H-3, J ) 8.0, 3.2
Hz), 4.23 (m, 1H, H-1), 4.52 (d, 1H, J ) 10.8 Hz), 4.53 (d, 1H,
J ) 12.4 Hz), 4.62 (d, 1H, J ) 11.2 Hz), 4.63 (d, 1H, J ) 12.4
Hz), 4.76 (d, 1H, J ) 11.2 Hz), 4.79 (d, 1H, J ) 10.8 Hz), 4.98
(dd, 1H, H-2, J ) 2.8, 2.8 Hz), 5.06-5.12 (m, 2H, -CHdCH2),
5.77 (m, 1H, -CHdCH2), 7.17-7.37 (m, 15H); 13C NMR
(CDCl3) δC 34.0, 39.2, 69.1, 72.9, 73.6, 73.7, 74.7, 75.0, 77.2,
78.4, 118.5, 127.8, 128.0, 128.2, 128.27, 128.5, 128.6, 128.7,
132.9, 137.3, 138.0, 138.3; HRFABMS Anal. calcd for C31H37O7S
[M + H] 553.2260, found 553.2282.
3-C-(3,4,6-Tri-O-benzyl-2-O-tosyl-r-D-mannopyran-
osyl)propene (3). To a solution of 2-OH derivative (0.502 g)
obtained by the same procedure described above in pyridine
(6 mL) was added p-toluenesulfonyl chroride (0.406 g, 2.13
mmol) at 0 °C. After 24 h the mixture was poured into water/
ethyl acetate. Usual workup and chromatography (hexane/
EtOAc 6:1) gave 3 (0.566 g, 85%) as a colorless oil: [R]D -0.61
FIGURE 1. A mechanism of epimerization and 1,2-migration.
CHART 1
1
(c 0.66, CHCl3); H NMR (CDCl3) δH 2.23 (dd, 2H, CH2CHd
CH2, J ) 6.8, 6.8 Hz), 2.40 (s, 3H, CH3), 3.63-3.77 (m, 4H,
H-4, H-5, H-6, H-6′), 3.83 (m, 1H, H-3), 4.06 (m, 1H, H-1), 4.42
(d, 1H, J ) 12.0 Hz), 4.46 (d, 1H, J ) 11.2 Hz), 4.50 (d, 1H, J
) 14.0 Hz), 4.53 (d, 1H, J ) 14.0 Hz), 4.56 (d, 1H, J ) 11.2
Hz), 4.68 (d, 1H, J ) 12.0 Hz), 4.79 (dd, 1H, H-2, J ) 3.2, 3.2
Hz), 4.97-5.06 (m, 2H, -CHdCH2), 5.68 (m, 1H, -CHdCH2),
7.15-7.80 (m, 19H); 13C NMR (CDCl3) δC 21.8, 34.3, 69.0, 72.3,
72.9, 73.5, 73.9, 74.3, 74.7, 76.3, 78.0, 118.3, 127.7, 127.9, 128.0,
128.1, 128.2, 128.3, 128.5, 128.6, 129.9, 133.3, 137.7, 138.0,
138.4; HRFABMS Anal. calcd for C37H41O7S [M + H] 629.2573,
found 629.2524.
molecular hetero-Michael addition by 5-OH to C1, rather
than an SN2 substitution at C2, led to the formation of
2-O-Ms-R-C-mannoside 4 and its â-anomer 33. Because
the 1,2-cyclopropanation from 4 was not reversible (see
Scheme 2) the equilibriums were eventually driven to the
formation of 10, which was then transformed to 11 (1,2-
migration) and 12. The direct evidence to support this
mechanism was provided by the isolation of deuterated
products, 11-D and 12-D (see Chart 1), when 2-O-Ms-R-
C-glucoside 9 was treated with NaOMe in MeOH-d4
overnight. Due to deuteration the proton resonances of
H-2 at 2.29 ppm and 1′-CH2 at 2.38 and 2.47 ppm in 11-D
disappeared, consequently, the double doublet aldehyde
proton at 9.54 ppm and doublet H-1 at 4.15 ppm became
two singlets, respectively. Similarly, two singlets, H-1 at
5.94 ppm and H-2′ at 6.47 ppm, were observed in 12-D.
In summary, we have described a 1,2-migration of the
2′-oxoalkyl group via 1,2-cyclopropanated sugars from
base treatment of 2′-oxoalkyl 2-O-Ms(Ts)-C-glycosides.
The ring opening of 1,2-cyclopropanated sugars by vari-
ous nucleophiles (alcohols, thiols, and azide) resulted in
the concomitant formation of 2-C-branched O-, S-â -
glycosides and glycosyl azides. The results also confirm
that the 1,2-cyclopropanation requires the 1,2-trans-
diaxial configuration, otherwise â-elimination dominates.
Due to the epimerization at C2 under basic conditions
this method can only be applied to prepare 1,2-trans 2-C-
branched â-glycosides.
2-C-(3,4,6-Tri-O-benzyl-2-O-mesyl-r-D-mannopyran-
osyl)acetaldehyde (4). A solution of 2 (122 mg, 0.221 mmol)
in CH2Cl2 (26 mL) was cooled in a dry ice/acetone bath. A
stream of ozone was passed into the solution through a
sintered-glass sprayer. When the starting material disap-
peared, the solution was concentrated to a residue. To the
above residue in glacial acetic acid (3 mL) was added zinc dust
(65 mg, 1.0 mmol) and the mixture was stirred at room
temperature overnight. Usual workup and chromatographic
purification (hexane/ethyl acetate 6:1-2:1) afforded 4 (106 mg,
1
87%) as a syrup: [R]D +0.3 (c 1.5, CHCl3); H NMR (CDCl3)
δH 2.66 (ddd, 1H, CHHCHO, J ) 16.4, 4.8, 1.2 Hz), 2.77 (ddd,
1H, CHHCHO, J ) 16.4, 8.8, 2.4 Hz), 2.97 (s, 3H, SO2CH3),
3.68 (dd, 1H, H-6, J ) 10.8, 4.0 Hz), 3.76-3.82 (m, 2H, H-4,
H-6′), 3.86 (dd, 1H, H-5, J ) 5.8, 5.6 Hz), 3.91 (dd, 1H, H-3, J
) 6.4, 2.8 Hz), 4.50 (d, 1H, J ) 12.0 Hz), 4.53 (d, 1H, J ) 11.2
Hz), 4.56 (d, 1H, J ) 12.0 Hz), 4.57 (d, 1H, J ) 12.0 Hz), 4.66
(d, 1H, J ) 11.2 Hz), 4.67 (d, 1H, J ) 12.0 Hz), 4.68 (m, 1H,
H-1), 4.90 (dd, 1H, H-2, J ) 5.6, 2.8 Hz), 7.20-7.33 (m, 15H),
9.74 (dd, 1H, CHO, J ) 2.0, 1.6 Hz); 13C NMR (CDCl3) δC 38.9,
44.7, 68.0, 68.3, 73.3, 73.6, 73.9, 74.3, 74.5, 74.7, 76.3, 77.4,
127.9, 128.0, 128.1, 128.3, 128.4, 128.6, 128.7, 128.7, 137.3,
137.7, 138.1, 199.5; HRFABMS Anal. calcd for C30H35O8S [M
+ H] 555.2053, found 555.2276.
2-C-(3,4,6-Tri-O-benzyl-2-O-tosyl-r-D-mannopyran-
osyl)acetaldehyde (5). Compound 3 (588 mg, 0.936 mmol)
was ozonized by the same procedure as described above.
Purification by chromatography (hexane/ethyl acetate 6:1-2:
1) gave 5 (501 mg, 85%) as a syrup: [R]D +3.6 (c 0.55, CHCl3);
1H NMR (CDCl3) δH 2.43 (s, 3H, CH3), 2.40-2.50 (m, 2H, CH2-
CHO), 3.62-3.68 (m, 2H, H-4, H-6), 3.78 (m, 1H, H-6′), 3.86-
3.96 (m, 2H, H-3, H-5), 4.39-4.55 (m, 7H, H-1, 3 × CH2Ph),
4.68 (d, 1H, H-2, J ) 8.0 Hz), 7.19-7.78 (m, 19H), 9.63 (s, 1H,
CHO); 13C NMR (CDCl3) δC 22.0, 44.6, 65.5, 68.0, 72.8, 73.4,
Experimental Section
3-C-(3,4,6-Tri-O-benzyl-2-O-mesyl-r-D-mannopyranosyl)-
propene (2). To a solution of 1 (0.76 g, 1.47 mmol) in MeOH
(9 mL) was added 1% NaOMe-MeOH (1 mL). After being
stirred for 30 min, the solution was neutralized by the addition
of glacial acetic acid, and the solvent was evaporated. The
residue was partitioned between EtOAc and water. The
organic solution was washed with water and brine, dried, and
J. Org. Chem, Vol. 70, No. 12, 2005 4731

Shao et al.
73.5, 74.5, 75.0, 75.3, 77.6, 127.9, 128.1, 128.2, 128.3, 128.6,
128.7, 130.2, 133.5, 137.6, 137.7, 138.3, 145.5, 199.6; HR-
FABMS Anal. calcd for C36H39O8S [M + H] 631.2366, found
631.2378.
General Procedures for 2-C-Branched Glycosyl Com-
pounds (11-29). Procedure A (for 11, 15 and 22): To a
solution of aldehyde (4 or 5) (50-100 mg, 0.1-0.2 mmol) and
nucleophile (2-3 equiv) (MeOH, AllOH, and NaN3) in MeOH
(5-10 mL) was added triethylamine (5-10 equiv). The solution
was stirred at room temperature overnight, and concentrated
to a residue. Purification was then performed on a silica gel
column.
Procedure B (for 12, 19, 20, 21, 23, and 24): To a solution
of aldehyde (5 or 6) (60-120 mg, 0.1-0.2 mmol) and nucleo-
phile (2-3 equiv) (MeOH, PhSH, 4-MeOPhSH, and 4-ClPhSH)
in MeOH (5-10 mL) was added K2CO3 (10 equiv). The
suspension was stirred at room temperature overnight. The
reaction mixture was filtrated and the filtrate was concen-
trated. Purification was then performed on a silica gel column.
Procedure C (for 14): Similar to Procedure A except EtOH
replaced MeOH.
1-C-(3,4,6-Tri-O-benzyl-2-O-tosyl-r-D-mannopyran-
osyl)acetone (6). To a solution of 3 (3.385 g, 5.39 mmol) and
Hg(OAc)2 (419 mg, 1.31 mmol) in acetone/water (4:1, 25 mL)
was added dropwise at 0 °C a solution of Jones reagent (2 M,
6 mL). The dark greenish-brown mixture was stirred for 3 h
at 0 °C and then poured into water (20 mL). The aqueous
mixture was extracted with EtOAc (3 × 20 mL). Usual workup
and chromatography (hexane/EtOAc 3:2) afforded 6 (2.611 g,
75%) as white powders: 1H NMR (CDCl3) δH 2.12 (s, 3H,
COCH3), 2.43 (s, 3H, CH3), 2.51-2.53 (m, 2H, CH2COCH3),
3.64 (dd, 1H, H-4, J ) 5.6, 4.0 Hz), 3.67-3.78 (m, 3H, H-3,
H-6, H-6′), 3.87 (m, 1H, H-5), 4.36-4.53 (m, 7H, H-1, 3 × CH2-
Ph), 4.79 (dd, 1H, H-2, J ) 7.2, 3.2 Hz), 7.16-7.79 (m, 19H);
13C NMR (CDCl3) δH 21.9, 30.9, 44.7, 67.1, 68.4, 73.0, 73.1,
73.5, 74.5, 74.9, 75.5, 77.5, 127.8, 127.9, 128.1, 128.3, 128.6,
130.1, 133.8, 137,7, 137.8, 138.4, 145.3, 205.7; HRFABMS
Anal. calcd for C37H41O8S [M + H] 645.7816, found 645.7809.
Procedure D (for 18): Similar to Procedure B except
MeCN replaced MeOH as a solvent.
Procedure E (for 16, and 17): Similar to Procedure B
without solvent MeOH.
3-C-(3,4,6-Tri-O-benzyl-2-O-mesyl-r-D-glucopyranosyl)-
propene (8). Compound 7 (7.33 g, 14.2 mmol) was converted
to 8 by the same procedure as described above for the
preparation of 2. Purification by chromatography (hexane/
EtOAc 3:1) gave 8 (6.43 g, 82%) as a syrup: [R]D +23.6 (c 0.5,
Procedure F (for 25, 26, 27, 28, and 29): A solution of 13
(50 mg, 0.11 mmol) and 3 equiv of MeOH, AllOH, BnOH,
NaN3/MeOH, or Solketal/DMF was stirred at difference tem-
peratures (see Table 2) for 16 h. Purification was then
performed on a silica gel column.
1
CHCl3); H NMR (CDCl3) δH 2.51 (dd, 2H, CH2CHdCH2, J )
Methyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-
â-D-glucopyranoside (11). Prepared by Procedure A and
purified by chromatography (hexane/EtOAc 6:1) (72%): [R]D
+12.8 (c 0.25, CHCl3); 1H NMR (CDCl3) δH 2.29 (m, 1H, H-2),
2.38 (ddd, 1H, CHHCHO, J ) 16.4, 6.8, 2.8 Hz), 2.47 (ddd,
1H, CHHCHO, J ) 16.4, 6.4, 2.4 Hz), 3.37 (dd, 1H, H-3, J )
19.6, 10.8 Hz), 3.45 (m, 1H, H-5), 3.46 (s, 3H, OCH3), 3.68 (dd,
1H, H-4, J ) 9.6, 8.8 Hz), 3.76 (d, 2H, H-6, H-6′, J ) 3.2 Hz),
4.15 (d, 1H, H-1, J ) 8.8 Hz), 4.54 (d, 1H, J ) 10.4 Hz), 4.57
(d, 1H, J ) 12.0 Hz), 4.60 (d, 1H, J ) 12.0 Hz), 4.66 (d, 1H, J
) 12.0 Hz), 4.79 (d, 1H, J ) 12.0 Hz), 4.88 (d, 1H, J ) 10.4
Hz), 7.17-7.37 (m, 15H), 9.54 (dd, 1H, CHO, J ) 2.8, 2.4 Hz);
13C NMR (CDCl3) δC 42.5, 44.0, 57.1, 68.9, 73.7, 74.9, 75.1, 75.3,
79.9, 82.5, 103.9, 127.8, 127.9, 128.2, 128.5, 128.6, 137.8, 138.0,
138.2, 201.2; HRFABMS Anal. calcd for C30H35O6 [M + H]
491.2435, found 491.2492.
7.5, 7.0 Hz), 2.85 (s, 3H, SO2CH3), 3.63-3.67 (m, 2H, H-5, H-6),
3.74-3.77 (m, 2H, H-4, H-6′), 3.87 (dd, 1H, H-3, J ) 9.0, 8.5
Hz), 4.33 (dd, 1H, H-1, J ) 13.5, 7.0 Hz), 4.49 (d, 1H, J ) 12.0
Hz), 4.53 (d, 1H, J ) 11.0 Hz), 4.63 (dd, 1H, H-2, J ) 9.0, 2.0
Hz), 4.64 (d, 1H, J ) 12.0 Hz), 4.74 (d, 1H, J ) 11.0 Hz), 4.75
(d, 1H, J ) 11.0 Hz), 4.90 (d, 1H, J ) 11.0 Hz), 5.11-5.17 (m,
2H, CHdCH2), 5.80 (m, 1H, CHdCH2), 7.12-7.34 (m, 15H);
13C NMR (CDCl3) δC 30.2, 38.0, 68.5, 71.7, 73.4, 73.8, 75.1, 75.6,
78.4, 79.5, 80.0, 118.0, 127.8, 128.0, 128.1, 128.6, 128.7, 128.8,
133.5, 137.8, 137.9, 138.1; HRFABMS Anal. calcd for C31H37O7S
[M + H] 553.2260, found 553.2294.
2-C-(3,4,6-Tri-O-benzyl-2-O-mesyl-r-D-glucopyranosyl)-
acetaldehyde (9). Compound 8 (278 mg, 0.503 mmol) was
converted to 9 by the same procedure as described above for
the preparation of 4. Purification by chromatography (hexane/
ethyl acetate 6:1-2:1) gave 9 (237 mg, 85%) as a syrup: [R]D
11-D: 1H NMR (CDCl3) δH 3.37 (d, 1H, H-3, J ) 8.4 Hz),
3.45 (m, 1H, H-5), 3.68 (dd, 1H, H-4, J ) 9.6, 8.8 Hz), 3.76 (d,
2H, H-6, H-6′, J ) 3.2 Hz), 4.15 (s, 1H, H-1), 4.54 (d, 1H, J )
10.8 Hz), 4.57 (d, 1H, J ) 12.0 Hz), 4.60 (d, 1H, J ) 12.0 Hz),
4.66 (d, 1H, J ) 12.0 Hz), 4.79 (d, 1H, J ) 12.0 Hz), 4.88 (d,
1H, J ) 10.8 Hz), 7.17-7.37 (m, 15H), 9.54 (s, 1H, CHO);
HRFABMS Anal. calcd for C30H29D6O6 [M + H] 497.2810,
found 497.2785.
1
+32.7 (c 1.5, CHCl3); H NMR (CDCl3) δH 2.80-2.83 (m, 2H,
CH2CHO), 2.86 (s, 3H, SO2CH3), 3.61 (dd, 1H, H-6, J ) 10.4,
2.4 Hz), 3.68 (m, 1H, H-5), 3.72-3.77 (m, 2H, H-4, H-6′), 3.81
(dd, 1H, H-3, J ) 8.8, 8.0 Hz), 4.47 (d, 1H, J ) 12.0 Hz), 4.53
(d, 1H, J ) 10.8 Hz), 4.60 (d, 1H, J ) 12.0 Hz), 4.67 (m, 1H,
H-2), 4.71(d, 1H, J ) 11.2 Hz), 4.72 (d, 1H, J ) 10.8 Hz), 4.86
(d, 1H, J ) 11.2 Hz), 4.92 (m, 1H, H-1), 7.13-7.35 (m, 15H),
9.74 (dd, 1H, CHO, J ) 2.8, 1.6 Hz); 13C NMR (CDCl3) δC 38.1,
41.3, 68.2, 68.8, 72.8, 73.8, 74.9, 75.5, 77.5, 78.1, 79.3, 127.9,
128.0, 128.1, 128.2, 128.3, 128.6, 128.7, 128.8, 137.7, 137.9,
199.0; HRFABMS Anal. calcd for C30H35O8S [M + H] 555.2053,
found 555.2136.
Bicyclic Compound 12. Obtained by Procedure B and
purified by chromatography (hexane/EtOAc 6:1) (15%): [R]D
1
+26.0 (c 0.1, CHCl3); H NMR (CDCl3) δH 3.17 (m, 1H, H-2),
3.63-3.70 (m, 4H, H-6, H-6′, H-3, H-4), 3.82 (m, 1H, H-5), 4.40
(d, 1H, J ) 11.6 Hz), 4.52 (d, 1H, J ) 12.4 Hz), 4.58 (d, 1H, J
) 11.6 Hz), 4.59 (d, 1H, J ) 12.4 Hz), 4.61 (s, 2H), 4.93 (dd,
1H, CHdCHO, J ) 2.8, 2.4 Hz), 5.94 (d, 1H, H-1, J ) 8.0 Hz),
6.47 (dd, 1H, CHdCHO, J ) 2.8, 2.8 Hz), 7.17-7.35 (m, 15H);
13C NMR (CDCl3) δC 44.1, 69.9, 71.3, 72.1, 72.9, 73.6, 75.8, 79.4,
102.4, 102.6, 127.7, 127.9, 128.0, 128.0, 128.5, 128.6, 128.7,
138.1, 138.3, 146.3; HRFABMS Anal. calcd for C29H31O5 [M +
H] 459.2171, found 459.2137.
1,2-Cyclopropanated Sugar 13. To a solution of 6 (202
mg, 0.31 mmol) in MeOH (3 mL) was added K2CO3 (128 mg,
0.93 mmol). The suspension was stirred at room temperature
overnight, the mixture was filtrated, and the filtrate was
concentrated. Purification by chromatography (hexane/EtOAc
4:1) afforded compound 13 (119 mg, 81%) as a syrup: [R]D +42
1
(c 0.1, CHCl3); H NMR (CDCl3) δH 1.98 (ddd, 1H, H-2, J )
12-D: 1H NMR (CDCl3) δH 3.63-3.70 (m, 4H, H-6, H-6′, H-3,
H-4), 3.82 (m, 1H, H-5), 4.40 (d, 1H, J ) 11.6 Hz), 4.52 (d, 1H,
J ) 12.4 Hz), 4.58 (d, 1H, J ) 11.6 Hz), 4.59 (d, 1H, J ) 12.4
Hz), 4.61 (s, 2H), 5.94 (s, 1H, H-1), 6.46 (s, 1H, CDdCHO),
7.17-7.35 (m, 15H); HRFABMS Anal. calcd for C29H29D2O5
[M + H] 461.2297, found 461.2313.
Ethyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-â-
D-glucopyranoside (14). Prepared by Procedure C and
purified by chromatography (hexane/EtOAc 6:1) (71%): [R]D
+0.8 (c 1.5, CHCl3); 1H NMR (CDCl3) δH 1.18 (t, 3H, CH3, J )
7.2, 5.6, 1.6 Hz), 2.26 (s, 3H, COCH3), 2.34 (dd, 1H, H-1′, J )
5.6, 1.6 Hz), 3.56 (dd, 1H, H-4, J ) 6.0, 6.0 Hz), 3.59 (dd, 1H,
H-6, J ) 10.0, 3.6 Hz), 3.70 (dd, 1H, H-6′, J ) 10.0, 5.6 Hz),
3.72-3.77 (m, 2H, H-3, H-5), 3.86 (dd, 1H, H-1, J ) 7.2, 1.6
Hz), 4.53 (s, 2H), 4.55 (d, 2H, J ) 11.6 Hz), 4.69 (d, 1H, J )
11.6 Hz), 4.71 (d, 1H, J ) 11.6 Hz), 7.22-7.34 (m, 15H); 13C
NMR (CDCl3) δC 26.8, 31.4, 33.1, 61.1, 69.4, 71.6, 73.5, 73.7,
74.5, 75.5, 76.3, 128.0, 128.1, 128.2, 128.6, 128.7, 138.0, 138.2,
205.4; HRFABMS Anal. calcd for C30H33O5 [M + H] 473.2328,
found 473.2583.
4732 J. Org. Chem., Vol. 70, No. 12, 2005

2-C-Branched O-, S-Glycosides and Glycosyl Azides
7.2 Hz), 2.30 (m, 1H, H-2), 2.36 (ddd, 1H, CHHCHO, J ) 22.8,
7.2, 3.2 Hz), 2.48 (ddd, 1H, CHHCHO, J ) 22.8, 5.2, 1.6 Hz),
3.37 (dd, 1H, H-3, J ) 10.0, 10.0 Hz), 3.43-3.49 (m, 2H, H-5,
OCHHCH3), 3.67 (dd, 1H, H-4, J ) 9.2, 9.2 Hz), 3.75 (d, 2H,
H-6, H-6′, J ) 2.8 Hz), 3.92 (m, 1H, OCHHCH3), 4.23 (d, 1H,
H-1, J ) 8.4 Hz), 4.53 (d, 1H, J ) 10.8 Hz), 4.57 (d, 1H, J )
12.4 Hz), 4.60 (d, 1H, J ) 12.0 Hz), 4.65 (d, 1H, J ) 12.4 Hz),
4.79 (d, 1H, J ) 12.0 Hz), 4.88 (d, 1H, J ) 10.8 Hz), 7.18-
7.36 (m, 15H), 9.56 (dd, 1H, CHO, J ) 2.8, 2.8 Hz); 13C NMR
(CDCl3) δC 15.2, 42.7, 44.0, 65.6, 69.0, 73.8, 75.0, 75.2, 75.3,
80.0, 82.6, 102.8, 127.8, 128.0, 128.1, 128.3, 128.5, 128.6, 128.7,
137.8, 138.0, 138.2, 201.4; HRFABMS Anal. calcd for C31H37O6
[M + H] 505.2590, found 505.2515.
Allyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-â-D-
glucopyranoside (15). Prepared by Procedure A and purified
by chromatography (hexane/EtOAc 6:1) (76%): [R]D +1.0 (c 0.8,
CHCl3); 1H NMR (CDCl3) δH 2.31-2.50 (m, 3H, H-2, CH2CHO),
3.38 (dd, 1H, H-3, J ) 10.8, 8.8 Hz), 3.45 (ddd, 1H, H-5, J )
9.6, 3.2, 3.2 Hz), 3.68 (dd, 1H, H-4, J ) 9.2, 9.2 Hz), 3.75 (d,
2H, H-6, 6′, J ) 3.2 Hz), 4.01 (m, 1H, CH2CHdCH2), 4.29 (d,
1H, H-1, J ) 8.4 Hz), 4.34 (m, 1H, CH2CHdCH2), 4.54 (d, 1H,
J ) 10.8 Hz), 4.56 (d, 1H, J ) 11.6 Hz), 4.60 (d, 1H, J ) 11.2
Hz), 4.65 (d, 1H, J ) 11.2 Hz), 4.79 (d, 1H, J ) 11.6 Hz), 4.87
(d, 1H, J ) 10.8 Hz), 5.21 (m, 2H, CH2CHdCH2), 5.86 (m, 1H,
CH2CHdCH2), 7.18-7.36 (m, 15H), 9.57 (dd, 1H, CHO, J )
2.8, 2.4 Hz); 13C NMR (CDCl3) δC 42.3, 43.9, 69.0, 70.4, 73.7,
74.9, 75.1, 75.4, 80.0, 82.5, 101.8, 118.0, 127.8, 127.9, 128.0,
128.1, 128.3, 128.6, 128.7, 133.9, 137.9, 138.1, 138.3, 201.4;
HRFABMS Anal. calcd for C32H37O6 [M + H] 517.2590, found
517.2582.
5-Hexenyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-
â-D-glucopyranoside (16). Prepared by Procedure E and
purified by chromatography (hexane/EtOAc 5:1) (78%): [R]D
+5.6 (c 0.5, CHCl3); 1H NMR (CDCl3) δH 1.41 (m, 2H, CH2-
CH2CHdCH2), 1.56 (m, 2H, CH2CH2O-), 2.05 (m, 2H, CH2-
CHdCH2), 2.27-2.49 (m, 3H, H-2, CH2CHO), 3.35-3.46 (m,
3H, H-3, OCHHCH2, H-5), 3.66 (dd, 1H, H-4, J ) 8.8, 8.8 Hz),
3.74 (s, 2H, H-6, 6′), 3.87 (m, 1H, OCHHCH2), 4.22 (d, 1H,
H-1, J ) 8.4 Hz), 4.54 (d, 1H, J ) 10.8 Hz), 4.56 (d, 1H, J )
12.4 Hz), 4.60 (d, 1H, J ) 12.4 Hz), 4.64 (d, 1H, J ) 12.4 Hz),
4.79 (d, 1H, J ) 12.4 Hz), 4.87 (d, 1H, J ) 10.8 Hz), 4.93-
5.01 (m, 2H, CH2CHdCH2), 5.78 (m, 1H, CH2CHdCH2), 7.18-
7.36 (m, 15H), 9.56 (s, 1H, CHO); 13C NMR (CDCl3) δC 25.5,
29.0, 33.6, 42.5, 44.0, 69.0, 70.0, 73.7, 75.0, 75.1, 75.4, 80.0,
82.5, 103.0, 114.8, 127.9, 128.0, 128.2, 128.3, 128.6, 128.7,
137.9, 138.1, 138.3, 138.8, 201.5; HRFABMS Anal. calcd for
C35H43O6 [M + H] 559.3060, found 559.3013.
127.3, 127.6, 127.7, 127.9, 128.1, 129.0, 137.1, 137.3, 137.5,
156.5, 200.0; HRFABMS Anal. calcd for C35H37O6 [M + H]
553.2590, found 553.2724.
Phenyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-
â-D-thioglucopyranoside (19). Prepared by Procedure B and
purified by chromatography (hexane/EtOAc 10:1-4:1) (86%):
[R]D +26.0 (c 0.2, CHCl3); 1H NMR (CDCl3) δH 2.29 (m, 1H,
H-2), 2.46 (ddd, 1H, CH2CHO, J ) 17.2, 7.2, 3.2 Hz), 2.83, (dd,
1H, CH2CHO, J ) 17.2, 3.6 Hz), 3.48-3.54 (m, 2H, H-3, H-5),
3.66 (m, 1H, H-4), 3.79 (m, 2H, H-6, H-6′), 4.50-4.87 (m, 7H,
H-1, 3 × CH2Ph), 7.22-7.53 (m, 20H), 9.50 (s, 1H, CHO); 13C
NMR (CDCl3) δC 43.1, 44.5, 69.3, 73.8, 75.1, 79.6, 79.9, 84.0,
87.0, 127.8, 127.9, 128.1, 128.3, 128.5, 128.7, 129.1, 132.5,
137.7, 138.0, 199.9; HRFABMS Anal. calcd for C35H37O5S [M
+ H] 569.2362, found 569.2298.
4-Methoxyphenyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-
2-deoxy-â-D-thioglucopyranoside (20). Prepared by Proce-
dure B and purified by chromatography (hexane/EtOAc 5:1)
(85%): [R]D +7.9 (c 0.63, CHCl3); 1H NMR (CDCl3) δH 2.22 (m,
1H, H-2), 2.44 (ddd, 1H, CHHCHO, J ) 17.2, 7.6, 3.2 Hz), 2.86
(dd, 1H, CHHCHO, J ) 17.2, 3.6 Hz), 3.45-3.50 (m, 2H, H-3,
H-5), 3.62 (dd, 1H, H-4, J ) 9.6, 9.6 Hz), 3.76 (s, 3H, OCH3),
3.79 (d, 2H, H-6, H-6′, J ) 2.8 Hz), 4.51(d, 1H, CH2Ph, J )
10.4 Hz), 4.52 (d, 1H, H-1, J ) 10.4 Hz), 4.56 (d, 1H, J ) 11.6
Hz), 4.63 (d, 1H, J ) 10.8 Hz), 4.64 (d, 1H, J ) 11.6 Hz), 4.77
(d, 1H, J ) 10.8 Hz), 4.84 (d, 1H, J ) 10.4 Hz), 6.73-7.48 (m,
19H), 9.50 (d, 1H, CHO, J ) 3.2 Hz); 13C NMR (CDCl3) δC 42.7,
44.4, 55.5, 69.2, 73.6, 75.0, 79.5, 79.8, 84.0, 87.1, 114.7, 122.2,
127.7, 127.8, 127.9, 128.0, 128.1, 128.3, 128.5, 128.6, 135.7,
137.7, 138.1, 138.5, 160.1, 200.2; HRFABMS Anal. calcd for
C36H39O6S [M + H] 599.2467, found 599.2498.
4-Chlorophenyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-
2-deoxy-â-D-thioglucopyranoside (21). Prepared by Proce-
dure B and purified by chromatography (hexane/EtOAc 4:1)
1
(83%): [R]D +5.6 (c 0.5, CHCl3); H NMR (CDCl3) δH 2.27 (m,
1H, H-2), 2.46 (ddd, 1H, CHHCHO, J ) 16.8, 6.8, 2.4 Hz), 2.79
(dd, 1H, CHHCHO, J ) 16.8, 3.2 Hz), 3.48-3.54 (m, 2H, H-3,
H-5), 3.64 (dd, 1H, H-4, J ) 9.6, 9.6 Hz), 3.76-3.78 (m, 2H,
H-6, H-6′), 4.52 (d, 1H, J ) 11.2 Hz), 4.55 (d, 1H, J ) 13.6
Hz), 4.58 (d, 1H, J ) 13.6 Hz), 4.62 (d, 1H, J ) 11.2 Hz), 4.65
(d, 1H, H-1, J ) 10.4 Hz), 4.78 (d, 1H, J ) 11.2 Hz), 4.86 (d,
1H, J ) 11.2 Hz), 7.15-7.46 (m, 19H), 9.50 (d, 1H, CHO, J )
2.4 Hz); 13C NMR (CDCl3) δC 42.8, 44.0, 69.1, 73.6, 75.0, 79.4,
79.7, 83.6, 86.6, 127.9, 128.0, 128.1, 128.2, 128.3, 128.6, 128.7,
129.3, 129.5, 131.1, 134.0, 137.8, 138.0, 138.4, 200.0; HR-
FABMS Anal. calcd for C35H36ClO5S [M + H] 603.1972, found
603.2012.
Benzyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-
â-D-glucopyranoside (17). Prepared by Procedure E and
purified by chromatography (hexane/EtOAc 6:1) (75%): [R]D
Azido 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-â-
D-glucopyranoside (22). Prepared by Procedure A and
purified by chromatography (hexane/EtOAc 5:1) (52%): [R]D
1
1
-28.0 (c 0.2, CHCl3); H NMR (CDCl3) δH 2.34-2.42 (m, 3H,
+4.6 (c 0.13, CHCl3); H NMR (CDCl3) δH 2.18 (m, 1H, H-2),
H-2, CH2CHO), 3.36 (dd, 1H, H-3, J ) 10.4, 9.2 Hz), 3.45 (ddd,
1H, H-5, J ) 10.0, 3.6, 3.6 Hz), 3.69 (dd, 1H, H-4, J ) 9.2, 9.2
Hz), 3.77 (s, 2H, H-6, 6′), 4.31 (d, 1H, H-1, J ) 8.4 Hz), 4.51
(d, 1H, J ) 10.8 Hz), 4.55 (d, 1H, J ) 11.6 Hz), 4.58 (d, 1H, J
) 12.4 Hz), 4.61 (d, 1H, J ) 10.8 Hz), 4.67 (d, 1H, J ) 12.4
Hz), 4.79 (d, 1H, J ) 10.8 Hz), 4.85 (d, 1H, J ) 10.8 Hz), 4.87
(d, 1H, J ) 11.6 Hz), 7.18-7.38 (m, 20H), 9.45 (dd, 1H, CHO,
J ) 2.4, 2.0 Hz); 13C NMR (CDCl3) δC 42.4, 43.9, 69.0, 71.0,
73.7, 74.9, 75.1, 75.4, 80.0, 82.6, 101.3, 127.9, 128.0, 128.2,
128.3, 128.5, 128.6, 128.7, 137.1, 137.9, 138.1, 138.3, 201.5;
HRFABMS Anal. calcd for C36H39O6 [M + H] 567.2747, found
567.2682.
2.39 (ddd, 1H, CH2CHO, J ) 2.6, 6.4, 17.0 Hz), 2.51 (ddd, 1H,
CH2CHO, J ) 1.6, 5.2, 16.8 Hz), 3.45 (dd, 1H, H-3, J ) 8.8,
10.4 Hz), 3.56 (m, 1H, H-5), 3.71 (dd, 1H, H-4, J ) 9.4, 9.4
Hz), 3.77-3.78 (m, 2H, H-6, H-6′), 4.51-4.88 (m, 7H, H-1, 3
× CH2Ph), 7.17-7.37 (m, 15H), 9.53 (s, 1H, CHO); 13C NMR
(CDCl3) δC 41.7, 43.1, 68.0, 73.3, 74.6, 75.1, 77.1, 78.9, 81.2,
89.2, 127.3, 127.4, 127.5, 127.6, 127.7, 128.0, 128.1, 137.0,
137.2, 137.4, 199.2; HRFABMS Anal. calcd for C29H33N3O5 [M
+ 2H] 503.2420, found 503.2590.
4-Methoxyphenyl 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-
2-deoxy-â-D-thioglucopyranoside (23). Prepared by Proce-
dure B and purified by chromatography (hexane/EtOAc 6:1)
1
Phenyl 3,4,6-Tri-O-benzyl-2-C-formylmethyl-2-deoxy-
â-D-glucopyranoside (18). Prepared by Procedure D and
purified by chromatography (hexane/EtOAc 4:1) (62%): [R]D
(83%): [R]D +5.0 (c 0.1, CHCl3); H NMR (CDCl3) δH 1.99 (s,
3H, COCH3), 2.13 (m, 1H, H-2), 2.57 (dd, 1H, CH2 COCH3, J
) 17.6, 6.4 Hz), 2.80 (dd, 1H, CH2 COCH3, J ) 17.6, 3.6 Hz),
3.49 (m, 1H, H-5), 3.59 (dd, 1H, H-4, J ) 8.8, 8.8 Hz), 3.70
(dd, 1H, H-3, J ) 8.8, 8.8 Hz), 3.75 (s, 3H, OCH3), 3.76-3.82
(m, 2H, H-6, H-6′), 4.52 (d, 1H, J ) 12.4 Hz), 4.55 (d, 1H, J )
13.2 Hz), 4.60-4.68 (m, 3H, H-1, CH2Ph), 4.77 (d, 1H, J )
13.2 Hz), 4.87 (d, 1H, J ) 12.4 Hz), 6.73-7.47 (m, 19H); 13C
NMR (CDCl3) δC 30.4, 42.8, 43.5, 55.5, 69.4, 73.6, 74.9, 75.0,
1
-12.5 (c 0.2, CHCl3); H NMR (CDCl3) δH 2.50-2.55 (m, 2H,
H-2, CH2CHO), 2.60 (m, 1H, CH2CHO), 3.52 (m, 1H, H-3), 3.62
(m, 1H, H-5), 3.74-3.82 (m, 3H, H-4, H-6 and H-6′), 4.53-
4.65 (m, 4H), 4.81-4.92 (m, 3H, H-1, CH2Ph), 6.99-7.38 (m,
20H), 9.66 (s, 1H, CHO); 13C NMR (CDCl3) δC 41.9, 43.5, 68.4,
73.3, 74.6, 74.7, 75.1, 79.3, 81.7, 100.4, 116.3, 122.3, 127.2,
J. Org. Chem, Vol. 70, No. 12, 2005 4733

Shao et al.
79.4, 80.0, 83.4, 87.0, 114.6, 127.7, 127.9, 128.0, 128.1, 128.5,
128.7, 135.4, 138.4, 207.2; HRFABMS Anal. calcd for C37H41O6S
[M + H] 613.2624, found 613.2685.
) 11.6 Hz), 4.91 (d, 1H, J ) 11.6 Hz), 5.00 (d, 1H, H-1, J )
2.8 Hz), 7.13-7.38 (m, 20H); 13C NMR (CDCl3) δC 30.3, 41.8,
42.0, 68.9, 69.4, 71.4, 73.8, 75.0, 75.2, 80.0, 80.7, 98.2, 127.8,
127.9, 128.0, 128.1, 128.2, 128.6, 128.7, 137.9, 138.2, 138.3,
138.7, 207.7; HRFABMS Anal. calcd for C37H41O6 [M + H]
581.2903, found 581.2886.
Azido 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-2-deoxy-â-
D-glucopyranoside (28). Prepared by Procedure F and puri-
fied by chromatography (hexane/EtOAc 4:1) (92%): [R]D +16.5
(c 0.8, CHCl3); 1H NMR (CDCl3) δH 2.00 (s, 3H, COCH3), 2.07
(m, 1H, H-2), 2.46 (dd, 1H, CH2COCH3, J ) 17.2, 5.2 Hz), 2.57
(dd, 1H, CH2COCH3, J ) 17.2, 5.6 Hz), 3.56-3.70 (m, 3H, H-5,
H-3, H-4), 3.77-3.78 (m, 2H, H-6, H-6′), 4.53 (d, 1H, J ) 11.2
Hz), 4.58 (d, 1H, J ) 12.0 Hz), 4.60 (d, 2H, J ) 10.8 Hz), 4.66
(d, 1H, J ) 10.8 Hz), 4.70 (d, 1H, H-1, J ) 9.6 Hz), 4.77 (d,
1H, J ) 11.2 Hz), 4.89 (d, 1H, J ) 12.0 Hz), 7.17-7.37 (m,
15H); 13C NMR (CDCl3) δC 30.2, 40.8, 44.1, 68.6, 73.8, 75.1
(2), 77.6, 79.7, 81.8, 89.7, 127.8, 128.0, 128.1, 128.3, 128.7,
128.8, 138.1, 138.2, 138.3, 207.1; HRFABMS Anal. calcd for
C30H34N3O5 [M + H] 516.2498, found 516.2433.
4-Chlorophenyl 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-
2-deoxy-â-D-thioglucopyranoside (24). Prepared by Proce-
dure B and purified by chromatography (hexane/EtOAc 4:1)
(85%): [R]D +15.3 (c 0.2, CHCl3); 1H NMR (CDCl3) δH 1.98 (s,
3H, COCH3), 2.18 (m, 1H, H-2), 2.56 (dd, 1H, CH2 COCH3, J
) 17.6, 5.6 Hz), 2.76 (dd, 1H, CH2 COCH3, J ) 17.6, 5.6 Hz),
3.50 (m, 1H, H-5), 3.61 (dd, 1H, H-4, J ) 8.4, 8.4 Hz), 3.70-
3.77 (m, 3H, H-3, H-6, H-6′), 4.53 (d, 1H, J ) 11.2 Hz), 4.54
(d, 1H, J ) 11.6 Hz), 4.61 (d, 2H, J ) 11.6 Hz), 4.77 (d, 1H, J
) 11.6 Hz), 4.80 (d, 1H, H-1, J ) 10.8 Hz), 4.88 (d, 1H, J )
11.2 Hz), 7.14-7.45 (m, 19H); 13C NMR (CDCl3) δC 30.2, 42.2,
43.4, 68.9, 73.6, 74.9, 75.0, 79.4, 80.0, 83.1, 87.0, 127.9, 128.0,
128.1, 128.6, 128.7, 129.5, 133.6, 138.2, 138.3, 138.4, 207.1;
HRFABMS Anal. calcd for C36H38ClO5S [M + H] 617.2128,
found 617.2198.
Methyl 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-2-deoxy-â-
D-glucopyranoside (25). Prepared by Procedure F and puri-
fied by chromatography (hexane/EtOAc 4:1) (95%): [R]D +9.8
(c 1.2, CHCl3); 1H NMR (CDCl3) δH 1.97 (s, 3H, COCH3), 2.10
(m, 1H, H-2), 2.38 (dd, 1H, CH2COCH3, J ) 16.0, 6.0 Hz), 2.47
(dd, 1H, CH2COCH3, J ) 16.0, 6.0 Hz), 3.37 (s, 3H, OCH3),
3.39-3.46 (m, 2H, H-5, H-3), 3.58 (dd, 1H, H-4, J ) 8.8, 8.8
Hz), 3.68-3.69 (m, 2H, H-6, 6′), 4.17 (d, 1H, H-1, J ) 8.8 Hz),
4.47 (d, 1H, J ) 11.2 Hz), 4.50 (d, 1H, J ) 11.2 Hz), 4.52 (d,
1H, J ) 11.2 Hz), 4.58 (d, 1H, J ) 11.2 Hz), 4.71 (d, 1H, J )
11.2 Hz), 4.82 (d, 1H, J ) 11.2 Hz), 7.10-7.29 (m, 15H); 13C
NMR (CDCl3) δC 29.8, 42.2, 45.1, 57.1, 69.1, 73.7, 74.9, 75.1,
75.3, 80.1, 82.5, 103.9, 127.8, 128.0, 128.1, 128.6, 128.7, 138.2,
138.3, 208.1; HRFABMS Anal. calcd for C31H37O6 [M + H]
505.2590, found 505.2612.
Bicyclic Compound 29. Prepared by Procedure F and
purified by chromatography (hexane/EtOAc 4:1) (72%) [R]D
1
-12.7 (c 0.3, CHCl3); H NMR (CDCl3) δH 2.11 (s, 3H, CH3),
3.53-3.55 (m, 3H, H-6, H-4, H-6′), 3.61 (m, 1H, H-2), 3.65 (m,
1H, H-5), 4.01 (d, 1H, J ) 11.2 Hz), 4.27 (d, 1H, J ) 11.2 Hz),
4.52 (d, 1H, J ) 12.4 Hz), 4.53 (m, 1H, H-3), 4.57 (d, 1H, J )
12.4 Hz), 4.62 (d, 1H, J ) 12.0 Hz), 4.70 (d, 1H, J ) 12.0 Hz),
6.21 (d, 1H, H-1, J ) 8.8 Hz), 7.05-7.43 (m, 16H, 3 × Ph, CHd
CCH3,); 13C NMR (CDCl3) δC 26.8, 40.6, 70.7, 70.8, 71.2, 71.6,
73.6, 75.5, 105.4, 127.8, 128.0, 128.4, 128.5, 128.6, 138.1, 138.2,
138.3, 158.4; HRFABMS Anal. calcd for C30H33O5 [M + H]
473.2328, found 473.2392.
2-C-(3,4,6-Tri-O-benzyl-2-O-mesyl-â-D-glucopyranosyl)-
acetaldehyde (30). A solution of 9 (56 mg, 0.1 mmol) in 5
mL of 4% NaOMe was stirred at room temperature for 4 h,
neutralized with acetic acid, and concentrated. The residue
was purified by flash chromatography (hexane/ethyl acetate
6:1-4:1) to afford 30 (34 mg, 60%) as a syrup: 1H NMR
(CDCl3) δH 2.80 (CH3SO2), 2.81 (m, 1H, CH2CHO), 2.95 (m,
1H, CH2CHO), 3.48 (m, 1H, H-5), 3.68-3.83 (m, 4H, H-3, H-4,
H-6, 6′), 3.80 (m, 1H, H-1), 4.40 (m, 1H, H-2), 4.52-5.25 (m,
6H), 7.15-7.38 (m, 15H), 9.80 (s, 1H, CHO); 13C NMR (CDCl3)
δC 38.4, 45.3, 68.0, 73.1, 73.5, 74.9, 75.3, 78.6, 79.1, 80.5, 83.6,
127.1, 127.6, 127.7, 127.8, 128.3, 128.4, 137.3, 137.4, 137.6,
198.8; HRFABMS Anal. calcd for C30H35O8S [M + H] 555.2053,
found 555.2006.
Allyl 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-2-deoxy-â-D-
glucopyranoside (26). Prepared by Procedure F and purified
by chromatography (hexane/EtOAc 6:1) (96%): [R]D +9.2 (c 1.0,
CHCl3); 1H NMR (CDCl3) δH 2.04 (s, 3H, COCH3), 2.21 (m, 1H,
H-2), 2.46 (dd, 1H, CH2COCH3, J ) 16.0, 6.0 Hz), 2.54 (dd,
1H, CH2COCH3, J ) 16.0, 6.0 Hz), 3.45-3.53 (m, 2H, H-5,
H-3), 3.65 (dd, 1H, H-4, J ) 9.6, 8.8 Hz), 3.74 (d, 2H, H-6, 6′,
J ) 3.2 Hz), 3.99 (dd, 1H, CH2CHdCH2, J ) 12.4, 6.4 Hz),
4.32 (dd, 1H, CH2CHdCH2, J ) 12.4, 5.2 Hz), 4.37 (d, 1H, H-1,
J ) 8.8 Hz), 4.53 (d, 1H, J ) 11.2 Hz), 4.55 (d, 1H, J ) 12.4
Hz), 4.56 (d, 1H, J ) 10.8 Hz), 4.65 (d, 1H, J ) 12.4 Hz), 4.78
(d, 1H, J ) 10.8 Hz), 4.88 (d, 1H, J ) 11.2 Hz), 5.19 (m, 2H,
CH2CHdCH2), 5.86 (m, 1H, CH2CHdCH2), 7.17-7.36 (m,
15H); 13C NMR (CDCl3) δC 29.8, 42.2, 45.1, 69.1, 70.3, 73.7,
74.9, 75.1, 75.3, 80.1, 82.5, 101.9, 117.8, 127.8, 128.0, 128.7,
134.0, 138.1, 138.3 (2), 208.1; HRFABMS Anal. calcd for
C33H39O6 [M + H] 531.2747, found 531.2702.
Benzyl 3,4,6-Tri-O-benzyl-2-C-acetylmethyl-2-deoxy-â-
D-glucopyranoside (27). Prepared by Procedure F and puri-
fied by chromatography (hexane/EtOAc 6:1) (82%): [R]D +112.2
(c 0.5, CHCl3); 1H NMR (CDCl3) δH 1.98 (s, 3H, COCH3), 2.44
(m, 1H, H-2), 2.48 (m, 1H, CH2COCH3), 2.65 (m, 1H, CH2-
COCH3), 3.65-3.74 (m, 3H, H-3, H-6, H-4), 3.77-3.85 (m, 2H,
H-6′, H-5), 4.38 (d, 1H, J ) 10.8 Hz), 4.53 (d, 1H, J ) 10.8
Hz), 4.54 (d, 1H, J ) 12.4 Hz), 4.58 (d, 1H, J ) 12.4 Hz), 4.65
(d, 1H, J ) 11.6 Hz), 4.68 (d, 1H, J ) 11.6 Hz), 4.77 (d, 1H, J
Acknowledgment. The authors thank Dr. Harry
Jennings for helpful discussion and Lisa Morrison for
mass spectrometric analysis.
Supporting Information Available: 1H, 13C, COSY,
NOESY, TOCSY, and HSQC NMR spectra for products 2-4,
6, 8-9, 11-D, 12-D, 16-17, and 25-30; for compounds 5, 11-
15, and 18-24 see ref 7. This material is available free of
charge via the Internet at http://pubs.acs.org.
JO0502854
4734 J. Org. Chem., Vol. 70, No. 12, 2005