1900
G. Bartoli et al.
LETTER
(16) A typical procedure for the cleavage of allyl ethers in
nitromethane is as follows: A solution of allyl ether (5
mmol) in nitromethane (25 mL) was treated with
+ H-CH3]+; 204 [M + H-alloc]+. Anal. Calcd for C11H18O8:C,
47.48; H, 6.52. Found: C, 47.5; H, 6.5. Methyl-6-O-
(allyloxycarbonyl)- -D-glucopyranoside. 88% Yield.
Syrup. H = 6.05–5.85 (m, 1 H, CH= ); 5.36 (ddd, Jt = 17.19
Hz, 4J = 2.94 Hz, 4J = 1.47 Hz, 1 H, =CHc); 5.27 (ddd, Jc =
10.23 Hz, 4J = 2.55 Hz, 4J = 1.08 Hz, 1 H, =CHt); 5.13 (brs,
1 H, OH); 4.75 (d, J1,2 = 3.66 Hz, 1 H, H1); 4.83–4.52 (m, 3
H, OCH2 + OH); 4.55 (dd, J2,3 = 9.84 Hz, J2,1 = 3.66 Hz, 1 H,
H2); 4.34 (dd, J4,5 = 11.70 Hz, J4,3 = 5.49 Hz, 1 H, H4); 4.00–
3.50 (m, 3 H, H3, H6), 3.40 (s, 3 H, OCH3), 3.00 (brs, 1 H,
OH). MS: m/z = 279 [M + H]+; 264 [M + H-CH3]+; 204 [M
+ H-alloc]+. Anal. Calcd for C11H18O8: C, 47.48; H, 6.52.
Found: C, 47.4; H, 6.5. Methyl-2,3,4-O-tris(allyloxy-
CeCl3 7H2O (7.5 mmol), NaI (7.5 mmol) and 1,3-
propanedithiol (7.5 mmol). The resulting mixture was
refluxed until GC analysis indicated that no starting material
remained. The reaction mixture was diluted with ether and
poured in 0.5 N HCl. The organic layer was separated, and
the aq layer washed with ether. The combined organic layers
were washed with NaHCO3 and water and then dried
(Na2SO4). All reaction mixtures were submitted to
quantitative GC analysis using the standard addition method.
All alcohols were then isolated by flash chromatography,
full NMR and IR data were compared with those of true
samples.
carbonyl)- -D-glucopyranoside. 75% Yield. Syrup.
=
H
6.02–5.87 (m, 3 H, CH= ); 5.42–5.26 (m, 6 H, =CH2); 5.10
(d, J1,2 = 3.61 Hz, 1 H, H1); 4.80 (t, J4,5 and J3,4 = 9.51 Hz, 1
H, H4); 4.70–4.64 (m, 6 H, OCH2); 4.58–4.53 (m, 1 H, H2);
4.25–4.15 (m, 1 H, H5); 3.81–3.65 (m, 2 H, H6), 3.40 (s, 3 H,
OCH3), 2.44 (brs, 1 H, OH). MS: m/z = 469 [M + Na]+; 447
[M + H]+; 385 [M + Na- Alloc]+, 367 [M + Na-Alloc-H2O]+.
Anal. Calcd for C19H26O12: C, 51.12; H, 5.87. Found: C,
51.0; H, 5.9. Methyl-2,3,4-O-tris(allyloxycarbonyl)- -D-
mannopyranoside. 60% Yield. Syrup. H = 6.02–5.87 (m, 3
H, CH= ); 5.42–5.26 (m, 6 H, =CH2); 5.25 (dd, J3,4 = 10.11
(17) (a) Gent, P. A.; Gigg, R.; Conant, R. J. Chem. Soc., Perkin
Trans. 1 1972, 1535. (b) Gigg, R. J. Chem. Soc., Perkin
Trans. 1 1980, 738. (c) Nashed, M. A.; Slife, C. W.; Kiso,
M.; Anderson, L. Carbohydr. Res. 1980, 82, 237. (d) Gigg,
R.; Conant, R. Carbohydr. Res. 1982, 100, C5.
(18) Physical data of selectively deprotected sugars follows:
Methyl 6-O-t-butyldiphenylsilyl- -D-glucopyranoside.
52% Yield. Mp 115 °C. H = 7.70–7.40 (m, 10 H); 4.75 (d,
J1,2 = 3.40 Hz, 1 H, H1); 3.90 (dd, J2,3 = 10.10 Hz, J2,1 = 3.40
Hz, 1 H, H2); 3.70–3.85 (m, 3 H, H3, H6); 3.65 (m, 2 H, H4,
H5); 3.35 (s, 3 H, OMe); 3.00 (brs, 1 H, OH); 2.85 (brs, 1 H,
OH); 1.05 (s, 9 H, t-Bu).MS: m/z = 454 [M + Na]+; 450 [M
+ NH4]+; 433 [M + H]+; 432 [M + NH4-MeOH]+; 401 [M –
MeOH]+. Anal. Calcd for C23H32O6Si: C, 63.86; H, 7.46.
Found: C, 64.0; H, 7.4. Methyl 6-O-(triphenylmethyl)- -
D-mannopyranoside. 80% Yield. Syrup. H = 7.44–7.23 (m,
15 H, ArH); 4.70 (d, J1,2 = 2.56 Hz, 1 H, H1); 3.90 (brs, 1 H,
OH); 3.80–3.50 (m, 6 H, H2, H3, H4, H5, H6), 2.20 (brs, 2 H,
OH).MS: m/z = 459 [M + Na]+; 437 [M + H]+; 243 [Tr]+; 215
[M + Na-Tr]+. Anal. Calcd for C26H28O6: C, 71.54; H, 6.47.
Found: C, 71.4; H, 6.5. Methyl-6-O-(allyloxycarbonyl)- -
D-mannopyranoside. 70% Yield. Syrup. H = 6.00–5.84 (m,
1 H, CH= ); 5.36 (dt, Jt = 17.39 Hz, 4J = 1.36 Hz, 1 H, =CHc);
5.27 (ddd, Jc = 10.57 Hz, 4J = 3.75 Hz, 4J = 1.36 Hz, 1
H, =CHt); 4.80–4.58 (m, 2 H, OCH2); 4.48 (brs, 1 H, OH);
4.46 (d, J1,2 = 11.59 Hz, 1 H, H1); 4.38 (dd, J1,2 = 11.59 Hz,
J2,3 = 5.80 Hz, 1 H, H2); 4.09 (t, J4,5 and J3,4 = 9.72 Hz, 1 H,
H4); 4.00–3.55 (m, 5 H, H3, H5, H6, 1 OH), 3.35 (s, 3 H,
OCH3), 2.90 (s, 1 H, OH). MS: m/z = 279 [M + H]+; 264 [M
Hz, J3,2 = 3.25 Hz, 1 H, H3); 5.17 (dd, J2,3 = 3.25 Hz, J2,1 =
1.81 Hz, 1 H, H2); 4.80 (d, J1,2 = 1.81 Hz, 1 H, H1); 4.68–4.63
(m, 6 H, OCH2); 4.63–4.61 (m, 1 H, H5); 4.13–4.03 (m, 1 H,
H4); 3.90 (brs, 1 H, OH); 3.76–3.69 (m, 2 H, H6); 3.41 (s, 3
H, OCH3). MS: m/z = 485 [M + K]+; 401 [M + K-Alloc]+;
331 [M + K-Alloc-MeOH]+; 199 [M + K-3Alloc-MeOH]+.
Anal. Calcd for C19H26O12: C, 51.12; H, 5.87. Found: C,
51.2; H, 5.9. Methyl-2,3,4-O-tris(allyloxycarbonyl)- -D-
galactopyranoside. 60% Yield. Syrup. H = 6.05–5.91 (m,
3 H, CH= ); 5.45–5.31 (m, 6 H, =CH2); 5.24 (d, J1,2 = 2.96
Hz, 1 H, H1); 5.19 (dd, J3,4 = 6.07 Hz, J3,2 = 2.96 Hz, 1 H,
H3); 5.13 (t, J2,3 and J2,1 = 2.96 Hz, 1 H, H2); 4.73–4.68 (m,
7 H, OCH2 + H5); 4.44 (d, J6,5 = 6.07 Hz, 2 H, H6); 4.31 (brs,
1 H, OH); 4.19–4.13 (m, 1 H, H4); 3.50 (s, 3 H, OCH3). MS:
m/z = 469 [M + Na]+; 447 [M + H]+; 367 [M + Na-Alloc-
H2O]+. Anal. Calcd for C19H26O12: C, 51.12; H, 5.87. Found:
C, 51.2; H, 5.8.
(19) Boullanger, P.; Chaterlard, P.; Descotes, G.; Kloosterman,
M.; van Boom, J. H. Carbohydr. Chem. 1986, 5, 541.
Synlett 2001, No. 12, 1897–1900 ISSN 0936-5214 © Thieme Stuttgart · New York