Prop-2-ynyl 4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-
enopyranoside (3d). Solid, mp 72–74 ЊC; [α]2D5 145 (c = 1.0,
CHCl3); 1H NMR (CDCl3, 200 MHz): δ 2.08 (s, 6H, COCH3),
2.40–2.45 (m, 1H, H-31), 4.05–4.15 (m, 1H, H-5), 4.18 (dd, 2H,
J = 4.9, 11.5 Hz, Ha-6, Hb-6), 4.25–4.30 (m, 2H, H-11), 5.20 (d,
1H, J = 1.2 Hz, H-1), 5.35 (dd, 1H, J = 1.2, 9.8 Hz, H-4), 5.85
(dd, 1H, J2,3 = 10.3 Hz, H-2), 5.87 (dd, 1H, J3,4 = 1.2 and 10.3
Hz, H-3). IR (KBr) ν: 3300, 2120, 1745, 1605 cm.Ϫ1. Anal. calcd
for C13H16O6 (268.26): C, 58.20; H, 6.01. Found: C, 58.18; H,
6.05%.
Hb-11), 4.10–4.15 (m, 1H, H-5), 4.20 (dd, 2H, J = 4.5 and 11.5
Hz, Ha-6, Hb-6), 5.12 (s, 1H, H-1), 5.35 (dd, 1H, J = 1.1 and 9.3
Hz), 5.85 (d, 1H, J2,3 = 10.3 Hz, H-2), 5.87 (dd, 1H, J3,4 = 1.2
and J2,3 = 10.3 Hz, H-3). 13CNMR (CDCl3, 50 MHz) δ: 19.9,
20.6, 20.8, 62.7, 65.0, 66.7, 66.9, 69.3, 80.8, 94.4, 127.3, 129.2,
170.1, 170.6. IR (KBr) ν: 3285, 2926, 2121, 1739, 1373 cm.Ϫ1
Anal. calcd for C14H18O6 (282.29): C, 59.57; H, 6.43. Found: C,
59.60; H, 6.45%.
Phenyl 4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-eno-
pyranoside (3k). Solid, mp 47–48 ЊC, [α]2D5 165.5 (c = 1.45,
C2H5OH); 1H NMR (CDCl3, 200 MHz) δ: 1.98 (s, 3H,
–COCH3), 2.09 (s, 3H, –COCH3), 4.13 (dd, 1H, J = 1.8 and 11.6
Hz, Ha-6), 4.20–4.25 (ddd, 1H, J = 1.8 and 5.0, 9.5 Hz, H-5),
4.28 (dd, 1H, J = 5.0, 11.6 Hz, Hb-6), 5.39 (dd, 1H, J = 1.0 and
9.5 Hz, H-4), 5.69 (d, 1H, J = 1.0 Hz, H-1), 5.98–6.03 (m, 2H,
H-2, H-3), 7.0–7.30 (m, 5H, Ar-H). 13C NMR (CDCl3,
50 MHz) δ: 20.4, 20.7, 29.6, 62.4, 64.9, 67.7, 92.6, 126.9, 129.8,
169.6, 170.0. Anal. calcd for C16H18O6 (306.31): C, 62.74; H,
5.92. Found: C, 62.80; H, 5.95%.
Allyl
4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-eno-
pyranoside (3e). Solid, mp 42–43 ЊC; [α]2D5 80.4 (c = 2.0, CHCl3);
1H NMR (CDCl3, 200 MHz) δ: 2.08 (s, 6H, –COCH3), 4.03–
4.30 (m, 5H, H-5, Ha-6, Hb-6, Ha-11, Hb-11), 5.08 (br s, 1H,
H-1), 5.22 (dq, 1H, J = 10.4, Ha-31), 5.28–5.38 (m, 2H, H-4,
Hb-31), 5.83–6.0 (m, 3H, H-2, H-3, H-21). 13C NMR (CDCl3, 50
MHz) δ: 20.75, 20.93, 62.91, 65.23, 66.91, 69.25, 93.66, 117.51,
127.71, 129.21, 134.04, 170.26, 170.75. IR (KBr) ν: 3375, 2926,
1733, 1535, 1441 cm.Ϫ1. Anal. calcd for C13H18O6(270.28): C,
57.78; H, 6.71. Found: C, 57.80; H, 6.74%.
p-Methoxyphenyl 4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-
hex-2-enopyranoside (3l). Solid, mp 69–70 ЊC; [α]2D5 123 (c = 1.5,
CHCl3); 1H NMR (CDCl3, 200 MHz) δ: 2.05 (s, 3H, COCH3),
2.15 (s, 3H, COCH3), 3.80 (s, 3H, –OCH3), 4.18 (dd, 2H, J = 5.0,
11.5 Hz, Ha-6, Hb-6), 4.25 (m, 1H, H-5), 5.35 (dd, 1H, J = 1.0
and 9.5 Hz, H-4), 5.51 (d, 1H, J = 1.1 Hz, H-1), 6.0 (br s, 2H,
H-2, H-3), 6.80 (d, 2H, J = 8.0 Hz, Ar-H), 7.05 (d, 2H, J =
8.0 Hz, Ar-H).
But-2-enyl
4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-
enopyranoside (3 f). [α]2D5 83.4 (c = 2.5, CHCl3); 1H NMR
(CDCl3, 400 MHz) δ: 1.75 (d, 3H, J = 6.5 H z, CH3–), 2.08 (s,
6H, –COCH3), 4.03–4.30 (m, 5H, H-5, Ha-6, Hb-6, Ha-11,
Hb-11), 5.03 (s, 1H, H-1), 5.30 (dd, 1H, J = 1.1, 9.5 Hz, H-4),
5.58–5.70 (m, 2H, Ha-21, Hb-21), 5.78–5.90 (m, 2H, H-2, H-3).
13C NMR (CDCl3, 50 MHz) δ: 17.5, 20.5, 20.7, 62.8, 63.3, 65.2,
66.7, 68.7, 93.1, 126.7, 127.7, 128.9, 130.0, 130.4, 169.9, 170.4.
IR (KBr) ν: 3378, 2920, 1745, 1546, 1451 cm.Ϫ1 Anal. calcd
for C14H20O6 (284.30): C, 59.15; H, 7.09. Found: C, 59.20; H,
7.13%.
p-Nitrophenyl 4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-
enopyranoside (3m). Solid, m.p 94–95 ЊC; [α]2D5 174 (c = 1.6,
CHCl3); 1H NMR (CDCl3, 200 MHz) δ: 1.97 (s, 3H, COCH3),
2.12 (s, 3H, COCH3), 4.11–4.19 (m, 2H, H-5, Ha-6), 4.27 (dd,
1H, J = 5.1 and 11.6 Hz, Hb-6), 5.41 (dd,1H, J = 1.2 and 9.5 Hz,
H-4), 5.81 (br s, 1H, H-1), 6.01 (dd, 1H, J = 1.2 and 10.2 Hz,
H-3), 6.11 (d, 1H, J = 10.2, H-2), 7.19 (d, 2H, J = 9.0 Hz, Ar-H),
8.20 (d, 2H, J = 9.0 Hz, Ar-H). 13C NMR (CDCl3, 50 MHz)
δ: 20.6, 20.9, 29.6, 62.4, 64.7, 68.4, 92.7, 116.7, 125.9, 131.2,
142.6, 161.9, 170.1, 170.5. Anal. calcd for C16H17NO8 (351.31):
C, 54.71; H, 4.88; N, 3.99. Found: C, 54.73; H, 4.90; N, 4.01%.
Benzyl
4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-eno-
1
pyranoside (3g). [α]2D5 125 (c = 1.8, CHCl3); H NMR (CDCl3,
200 MHz) δ: 2.10 (s, 6H, –COCH3), 4.11–4.16 (m, 2H, H-5,
Ha-6), 4.24 (dd, 1H, J = 5.0, 11.5 Hz, Hb-6), 4.60 (d, 1H, J = 11.7
Hz, CH2–Ph), 4.80 (d, 1H, J = 11.7 Hz, CH2–Ph), 5.13 (d, 1H,
J1,2 = 1.2 Hz, H-1), 5.35 (dd, 1H, J3,4 = 1.2 Hz, J4,5 = 9.7 Hz,
H-4), 5.82–5.92 (m, 2H, H-2, H-3), 7.30–7.40 (m, 5H,
aromatic). Anal. calcd for C17H20O6 (320.33): C, 63.74; H, 6.29.
Found: C, 63.8; H, 6.31%.
p-Bromophenyl 4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-
2-enopyranoside (3n). [α]2D5 117 (c = 1.2, CHCl3); 1H NMR
(CDCl3, 400 MHz) δ: 2.0 (s, 3H, COCH3), 2.15 (s, 3H, COCH3),
4.12–4.32 (m, 3H, H-5, Ha-6, Hb-6), 5.40 (dd, 1H, J = 1.2 and
9.5 Hz, H-4), 5.68 (s, 1H, H-1), 5.98–6.02 (m, 2H, H-2, H-3),
7.02 (d, 2H, J = 8.0 Hz, Ar-H), 7.42 (d, 2H, J = 8.0 Hz,
Ar-H).13C NMR (CDCl3, 50 MHz) δ: 20.6. 20.8, 29.6, 62.5,
64.9, 67.9, 93.0, 114.8, 118.8, 123.4, 126.6, 129.7, 130.4, 132.3,
156.1, 170.1, 170.5. Anal. calcd for C16H17BrO6 (385.20): C,
49.89; H, 4.45; Br, 20.74. Found: C, 49.90; H, 4.48; Br, 20.76%.
Ethyl
4,6-di-O-acetyl-2,3-dideoxy-ꢀ-D-erythro-hex-2-eno-
1
pyranoside (3h). [α]2D5 111 (c = 1.0, CHCl3), H NMR (CDCl3,
200 MHz) δ: 1.25 (t, 3H, J = 6.5 Hz, CH3), 2.10 (s, 6H,
–COCH3), 3.50–3.60 (m, 1H, –OCH2–), 3.75–3.85 (m, 1H,
–OCH2–), 4.05–4.10 (m, 1H, H-5), 4.15 (dd, 1H, J = 4.8, 11.6
Hz, Ha-6), 4.25 (dd, 1H, J = 4.8, 11.5 Hz, Hb-6), 5.0 (s, 1H,
H-1), 5.30 (dd, 1H, J3,4 = 1.1 Hz, J4,5 = 9.8 Hz, H-4), 5.80–5.90
(m, 2H, H-2 and H-3). 13C NMR (CDCl3, 50 MHz) δ: 15.2,
20.7, 20.9, 63.3, 64.2, 65.2, 66.7, 94.1, 127.9, 128.9, 170.2, 170.7.
Anal. calcd for C12H18O6 (258.27): C, 55.81; H, 7.02. Found: C,
55.83; H, 7.07%.
Acknowledgements
BVS and JSS thank CSIR, New Delhi, for the award of
fellowships.
Butyl 4,6-di-O-acetyl 2,3-dideoxy-ꢀ-D-erythro-hex-2-eno-
pyranoside (3i). [α]2D5 61.0 (c = 1.0, CHCl3); H NMR (CDCl3,
1
200 MHz) δ: 0.92 (t, 3H, J = 6.7 Hz, CH3), 1.30–1.49 (m, 2H,
CH3–CH2–),1.58–1.63 (m, 1H, CH3–CH2–CH2–), 2.06 (s, 6H,
COCH3), 3.43–3.52 (m, 1H, –OCH2–), 3.70–3.81 (m, 1H,
–OCH2–), 4.0–4.10 (m, 1H, H-5), 4.18–4.23 (m, 2H, Ha-6,Hb-6),
4.98 (s, 1H, H-1), 5.35 (dd, 1H, J3,4 = 1.2 Hz, J4,5 = 9.3 Hz, H-4),
5.80–5.85 (m, 2H, H-2, H-3). Anal. calcd for C14H22O6 (286.32):
C, 58.73; H, 7.74. Found: C, 58.75; H, 7.75%.
References and notes
1 Recent reviews on ionic liquids: (a) T. Welton, Chem. Rev., 1999, 99,
2071; (b) P. Wasserscheid and W. Keim, Angew. Chem. Int. Ed., 2000,
39, 3772.
2 Catalytic reactions in ionic liquids: R. Sheldon, Chem. Commun.,
2001, 2399.
3 (a) Bronsted acidic ionic liquids as dual solvent and catalysts:
A. C. Cole, J. L. Jensen, I. Ntai, K. L. T. Tran, K. J. Weaver,
D. C. Forbes and J. H. Jr. Davis, J. Am. Chem. Soc., 2002, 124, 5962;
ionic liquids have already been described as catalysts; (b) C. Wheeler,
K. N. West, C. L. Liotta and C. A. Eckert, Chem. Commun.,
2001, 887; (c) J. Peng and Y. Deng, Tetrahedron Lett., 2001, 42, 5917;
But-3-ynyl 4,6-di-O-acetyl 2,3-dideoxy-ꢀ-D-erythro-hex-2-
enopyranoside (3j). [α]2D5 45.4 (c = 2.5, CHCl3); 1H NMR (CDCl3,
400 MHz) δ: 1.98 (m, 1H, H-41), 2.07 (s, 6H), 2.55–2.60 (m, 2H,
Ha-21, Hb-21), 3.65–3.73 (m, 1H, Ha-11), 3.85–3.95 (m, 1H,
J. Chem. Soc., Perkin Trans. 1, 2002, 2390–2394
2393