2046
P. F. Tankam et al. / Carbohydrate Research 342 (2007) 2031–2048
2
3
12-Ha,b, J12a,12b = 16.2), 4.77 (d, 1H, 1-H, J1,2 = 3.6).
13C NMR (100.6 MHz, CDCl3): d 102.61 (s, C-13),
101.54 (s, C-9), 98.14 (d, C-1), 92.01 (s, C-14), 91.92
(s, C-10), 81.07 (d, C-3), 79.74 (d, C-2), 70.78 (d, C-5),
70.15 (d, C-4), 62.65 (t, C-6), 61.16 (t, C-12), 59.38 (t,
3.27. Methyl 2,3-di-O-(4-hydroxy-4-methyl-pent-2-ynyl)-
a-D-glucopyranoside (17e)
According to general procedure (b), 295 mg (1.09 mmol)
of 16 in 6 mL of THF was metalated with 7.0 mL of n-
butyl lithium solution (11.2 mmol, 1.6 M in hexane).
After quenching with acetone (1.2 mL, 16.34 mmol)
and work-up (see above), three fractions were obtained:
fraction 1: 29 mg (10%) of substrate 16, fraction 2: 17f
(108 mg, 30%) as a mixture of positional isomers, frac-
tion 3 (54 mg, 13%) of 17e: viscous oil. 1H NMR
(400.1 MHz, CDCl3, J in Hz): d 1.50 (s, 6H, 17-,
190-H), 1.51 (s, 6H, 12-, 120-H), 3.26 (br s, 2H, 2OH),
3.44 (s, 3H, 7-H, OCH3), 3.59–3.90 (m, 6H, 2-, 3-, 4-,
5-H and 6-Ha,b), 4.04 (br s, 2H, 2OH), 4.29–4.58 (m,
C-8), 55.20 (q, C-7), ꢀ0.23 (q, C-11), ꢀ0.28 (q, C-15).
ꢀ1
~
IR (diamond-ATR): m ¼ 3463 cm (br vs), 2961 (m),
2912 (m), 2848 (w), 2189, 2172 (w), 1345 (m), 1150
(m), 1088 (s), 1047 (vs). UV (acetonitrile): kmax (lge) =
191 nm (3.49), 195 (3.40), 205 (3.14), 218 (2.59), 224
(2.42). EIMS (70 eV): m/z (%) = 414 (7) [M+], 341 (1),
303 (2), 293 (6), 280 (6), 183 (21), 171 (39), 111
(61), 83 (58), 73 (100). Anal. Calcd for C19H34-
O6Si2 (414.64): C, 55.04; H, 8.26. Found: C, 54.91; H,
8.33.
3
4H, 8-, 13-Ha,b), 4.90 (d, 1H, 1-H, J1,2 = 3.5). 13C
3.26.1. Side products: Mixture of methyl 2-O-propargyl-
3-O-(3-trimethylsilyl-prop-2-ynyl)-a-D-glucopyranoside and
methyl 3-O-propargyl-2-O-(3-trimethylsilyl-prop-2-ynyl)-
a-D-glucopyranoside (17d). 1H NMR (400.1 MHz,
CDCl3, J in Hz): d 0.00 (2s, 18H, 11-, 140-H), 1.62 (br
s, 4H, 4 OH), 2.28 and 2.31 (2t, 2H, 14-H and 100-H,
NMR (100.6 MHz, CDCl3): d 97.88 (d, C-1), 91.80 (s,
C-10), 91.71 (s, C-15), 80.46 (d, C-3), 78.84 (d, C-2),
78.47 (s, C-14), 77.55 (s, C-9), 71.01 (d, C-5), 69.40 (d,
C-4), 64.80 (s, C-16), 64.77 (s, C-11), 61.68 (t, C-6),
60.59 (t, C-13), 58.50 (t, C-8), 55.25 (q, C-7), 31.23 (q,
C-12), 31.17 (q, C-17, -170ꢀ),1 31.12 (q, C-120). IR
4
4
J14,12 = 2.4, J10 ,8 = 2.4), 3.26 (s, 6H, 7-, 70-H,
(diamond-ATR): m ¼ 3379 cm (br vs), 2981 (m), 2934
0
0
~
OCH3), 3.32–3.71 (m, 12H, 2-, 20-, 3-, 30-, 4-, 40-, 5-,
(m), 1456 (m), 1361 (s), 1168 (s), 1090, 1065 (vs), 1038
(vs). UV (acetonitrile): kmax (lge) = 193 nm (3.44), 197
(3.20). GC–MS: m/z (%) = 368 (3) [M+ꢀH2O], 265 (7),
252 (7) , 169 (17), 157 (57), 97 (59), 80 (74), 43 (100).
HRMS: C19H30O8–H2O@C19H28O7: calcd 368.183,
found m/z 368.181 6 ppm. Anal. Calcd for C19H30O8
(386.44): C, 59.05; H, 7.82; Found: C, 55.75; H,
7.66.
50-H and 6-, 60-Ha,b), 4.05–4.34 (m, 8H, 8-, 12-Ha,b
,
3
and 80-, 110-Ha,b), 4.74 (d, 2H, 1-, 10-H, J1,2 = 3.5,
3
J1 ,2 = 3.6). 13C NMR (100.6 MHz, CDCl3): d 101.43
(s, C-9), 98.07 (d, C-1), 98.00 (d, C-10), 92.02 (s, C-10),
81.07 (d, C-3), 80.57 (d, C-3, -13), 79.82 (d, C-2), 75.00
(d, C-100), 74.85 (d, C-14), 70.66 (d, C-5), 70.15 (d, C-
40), 70.07 (d, C-4), 62.50 (t, C-6), 60.26 (t, C-12),
59.31 (t, C-8), 55.20 (q, C-7), ꢀ0.24 (q, C-11), ꢀ0.28
0
0
0
ꢀ1
~
(q, C-14 ). IR (diamond-ATR): m ¼ 3403 cm (br vs),
3291 (m), 2958 (m), 2928 (m), 2853 (w), 2177 (w),
2118 (w), 1450 (m), 1358 (m), 1153 (m), 1088 (vs),
1045 (vs).
3.27.1. Side products: Mixture of methyl 3-O-(4-hydroxy-
4-methyl-pent-2-ynyl)-2-O-propargyl-a-D-glucopyranoside
and methyl 2-O-(4-hydroxy-4-methyl-pent-2-ynyl)-3-O-
propargyl-a-D-glucopyranoside (17f). 1H NMR (400.1
MHz, CDCl3, J in Hz): d 1.50–1.51 (s, s, 12H, 12-,
1200-H and 150-, 1500-H), 2.49, 2.52 (t, t, 2H, 15-, 100-H,
3.26.2. Methyl 4,6-di-O-(trimethylsilyl)-2,3-di-O-(3-tri-
methylsilyl-prop-2-ynyl)-a-D-glucopyranoside (17c). 1H
NMR (400.1 MHz, CDCl3, J in Hz): d 0.00 (s, s, 18H,
11-, 16-H), 0.02 (s, 9H, 17-H), 0.03 (s, 9H, 15-H), 3.26
(s, 3H, 7-H, OCH3), 3.27–3.75 (m, 6H, 2-, 3-, 4-, 5-H
and 6-Ha,b), 4.12–4.34 (m, 4H, 8-, 12-Ha,b), 4.63 (d,
4
4
0
0
J15,13 = 2.4, J10 ,8 = 2.4), 2.88 (br s, 6H, 6 OH), 3.44
(s, s, 6H, 7-, 70-H, OCH3), 3.54–3.86 (m, 12H, 2-, 20-,
3-, 30-, 4-, 40-, 5-, 50-H and 6-, 60-Ha,b), 4.28–4.56 (m,
8H, 8-, 13-Ha,b and 80-, 110-Ha,b), 4.90–4.92 (m, 2H, 1-,
10-H). 13C NMR (100.6 MHz, CDCl3): d 97.99 (d, C-
10), 97.95 (d, C-1), 91.71 (s, C-10), 91.67 (s, C-130),
80.61 (d, C-3), 80.51 (d, C-30), 79.63 (s, C-90, -14),
79.20 (d, C-20), 79.04 (d, C-2), 78.63 (s, C-120), 77.66
(s, C-9), 75.05 (d, C-100), 74.92 (d, C-15), 70.93 (d, C-
50), 70.88 (d, C-5), 69.76 (d, C-40), 69.64 (d, C-4),
64.88 (s, C-11, -140), 62.05 (t, C-6), 61.93 (t, C-60),
60.48 (t, C-110), 60.31 (t, C-13), 58.60 (t, C-8), 58.36
(t, C-80), 55.19 (q, C-7, -70), 31.21 (q, C-12, -1200),
3
1H, 1-H, J1,2 = 3.6). 13C NMR (100.6 MHz, CDCl3):
d 102.87 (s, C-13, -13), 97.70 (d, C-1), 91.78 (s, C-10,
-14), 80.12 (d, C-3), 79.31 (d, C-2), 70.68 (d, C-5),
70.31 (d, C-4), 62.92 (t, C-6), 60.90 (t, C-8, -12), 55.42
(q, C-7), 0.06 (q, C-16), ꢀ0.06 (q, C-11), ꢀ0.26 (q,
~
C-15), ꢀ1.93 (q, C-17). IR (diamond-ATR): m ¼
2960 cmꢀ1 (m), 2905 (m), 2178 (w), 1450 (m), 1366
(m), 1150 (m), 1040 (vs). UV (acetonitrile): kmax
(lge) = 193 nm (3.95), 200 (3.93), 208 (4.01), 216
(4.06), 224 (3.90). GC–MS: m/z (%) = 558 (62) [M+],
271 (68), 255 (11), 197 (8), 171 (8), 155 (56), 111 (27),
83 (23), 73 (100). HRMS: C25H50O6Si4: calcd 558.268,
found m/z 558.270 4 ppm.
31.16 (q, C-150, -1500). IR (diamond-ATR): m ¼
~
3392 cmꢀ1 (br s), 3289 (s), 2981 (m), 2932 (m), 2117
(w), 1451 (m), 1362 (s), 1158 (s), 1091 (vs), 1053
(vs). UV (acetonitrile): kmax (lge) = 191 nm (3.46), 208
(3.28).