1832
R. D. Wakharkar et al.
PAPER
allyl alcohol (20 mL, 300 mmol). The mixture was stirred vigorous-
ly at 25 °C for 12–15 h, filtered and the filtrate passed through a col-
umn of Amberlite IRA 400 (HO–) resin packed in allyl alcohol (15
mL). The resin was washed with allyl alcohol (30 mL) and the com-
bined eluents and washings were concentrated. The residue was
dried and used without any further purification for the next transfor-
mation. To an ice-cold solution of allyl-(a/b)-D/L-lyxofuranoside
(obtained as above) in acetone (20 mL) was added of p-toluene-
sulfonic acid (20 mg), followed by addition of 2,2-dimethoxypro-
pane (1.2 mL, 10 mmol). The reaction mixture was stirred at r.t. for
30 min. Sat. NaHCO3 was added to the reaction mixture and the ac-
etone was concentrated. Then the residue was extracted with EtOAc
(2 × 50 mL) and the combined organic layers were washed with
H2O, brine, dried (Na2SO4) and concentrated. The crude product
was purified on silica gel with petroleum ether–EtOAc as eluent to
give the corresponding allyl 2,3-O-isopropylidene-(a/b)-D/L-lyxo-
furanoside; yield: from D-lyxose: 83% (a:b = 1.2:1) and from L-lyx-
ose: 82% (a:b = 1.2:1).
13C NMR (CDCl3): d = 25.6, 27.5, 62.8, 67.3, 68.7, 74.5, 76.5, 97.7,
109.4, 117.9, 133.4.
MS: m/z (%) = 215 (8, [M – 15]+), 59 (100).
Anal. Calcd for C11H18O5: C, 57.38; H, 7.88. Found: C, 57.44; H,
7.70.
Alkyl 2,3-O-Isopropylidene-5-O-methoxymethylfuranosides 4–
11; General Procedure
To an ice-cold solution of the alkyl 2,3-O-isopropylidenefuranoside
derivative (1 mmol) in CH2Cl2 (15 mL) was added diisopropyleth-
ylamine (0.9 mL, 5 mmol) and methoxymethyl chloride (0.4 mL, 5
mmol). The reaction mixture was stirred at 0 °C for 1 h and over-
night at r.t. It was then diluted with CH2Cl2 (50 mL) and then
washed with sat. NaHCO3, brine, dried (Na2SO4) and concentrated.
The residue was purified on silica gel using petroleum ether–EtOAc
as an eluent to give the corresponding alkyl 2,3-O-isopropylidene-
5-O-methoxymethylfuranoside derivatives 4–11.
Allyl 2,3-O-Isopropylidene-5-O-methoxymethyl-b-D-lyxofura-
noside (4)
Yield: 91%; colourless syrup; [a]D +64 (c = 1, CHCl3).
1H NMR (CDCl3): d = 1.29 (s, 3 H), 1.46 (s, 3 H), 3.31 (s, 3 H),
3.41–3.64 (m, 2 H), 3.68–3.78 (m, 1 H), 3.89–4.23 (m, 4 H), 4.63
(d, J = 6.6 Hz, 1 H), 4.71 (d, J = 6.6 Hz, 1 H), 4.83 (d, J = 2.1 Hz,
1 H), 5.11–5.30 (m, 2 H), 5.75–5.95 (m, 1 H).
13C NMR (CDCl3): d = 26.2, 27.8, 55.2, 59.6, 68.1, 73.0, 75.4, 76.5,
95.8, 97.2, 109.0, 117.3, 133.7.
MS: m/z (%) = 259 (17, [M – 15]+), 45 (100).
Allyl 2,3-O-Isopropylidene-a-D-lyxofuranoside (16)
Colourless syrup; [a]D +75 (c = 1.5, CHCl3).
1H NMR (CDCl3): d = 1.30 (s, 3 H), 1.46 (s, 3 H), 3.00 (br s, 1 H),
3.92–3.95 (m, 2 H), 3.99 (dt, J = 5.8, 1.2 Hz, 1 H), 4.06–4.21 (m, 2
H), 4.63 (d, J = 6.0 Hz, 1 H), 4.80 (dd, J = 6.0, 3.7 Hz, 1 H), 5.09
(br s, 1 H), 5.16–5.31 (m, 2 H), 5.78–5.97 (m, 1 H).
13C NMR (CDCl3): d = 24.4, 25.8, 60.6, 67.7, 79.6, 80.0, 85.1,
105.2, 112.5, 117.2, 133.7.
MS: m/z (%) = 215 (7, [M – 15]+), 59 (100).
Anal. Calcd for C11H18O5: C, 57.38; H, 7.88. Found: C, 57.36; H,
7.67.
Anal. Calcd for C13H22O6: C, 56.92; H, 8.08. Found: C, 57.16; H,
8.33.
Allyl 2,3-O-Isopropylidene-b-D-lyxofuranoside (3)
Colourless solid; mp 47 °C; [a]D +58 (c = 1, CHCl3).
Allyl 2,3-O-Isopropylidene-5-O-methoxymethyl-b-L-lyxofura-
noside (5)
Yield: 79%; colourless syrup; [a]D –66 (c = 1.6, CHCl3).
1H NMR (CDCl3): d = 1.35 (s, 3 H), 1.52 (s, 3 H), 3.37 (s, 3 H),
3.47–3.69 (m, 2 H), 3.71–3.83 (m, 1 H), 3.94–4.28 (m, 4 H), 4.67
(d, J = 6.8 Hz, 1 H), 4.76 (d, J = 6.8 Hz, 1 H), 4.87 (d, J = 2.0 Hz, 1
H), 5.16–5.36 (m, 2 H), 5.80–6.00 (m, 1 H).
13C NMR (CDCl3): d = 26.2, 27.8, 55.2, 59.7, 68.2, 73.1, 75.4, 76.6,
95.9, 97.2, 109.1, 117.4, 133.7.
MS: m/z (%) = 259 (13, [M – 15]+), 45 (100).
1H NMR (CDCl3): d = 1.29 (s, 3 H), 1.44 (s, 3 H), 2.56 (br s, 1 H),
3.63 (dd, J = 11.0, 5.9 Hz, 1 H), 3.68–3.80 (m, 2 H), 3.98 (br ddt,
J = 12.8, 6.0, 1.3 Hz, 1 H), 4.08 (dd, J = 5.9, 2.9 Hz, 1 H), 4.11–4.27
(m, 2 H), 4.74 (d, J = 2.5 Hz, 1 H), 5.05–5.35 (m, 2 H), 5.70–5.95
(m, 1 H).
13C NMR (CDCl3): d = 25.6, 27.5, 62.6, 67.2, 68.5, 74.5, 76.7, 97.6,
109.3, 117.7, 133.3.
MS: m/z (%) = 215 (14, [M – 15]+), 100 (100).
Anal. Calcd for C11H18O5: C, 57.38; H, 7.88. Found: C, 57.16; H,
8.08.
Anal. Calcd for C13H22O6: C, 56.92; H, 8.08. Found: C, 57.11; H,
8.31.
Allyl 2,3-O-Isopropylidene-a-L-lyxofuranoside (17)
Colourless syrup; [a]D –77 (c = 1, CHCl3).
1H NMR (CDCl3): d = 1.27 (s, 3 H), 1.43 (s, 3 H), 2.73 (br s, 1 H),
3.87–3.90 (m, 2 H), 3.94–3.99 (m, 1 H), 4.02–4.18 (m, 2 H), 4.60
(d, J = 5.9 Hz, 1 H), 4.76 (dd, J = 5.9, 3.7 Hz, 1 H), 5.05 (s, 1 H),
5.12–5.29 (m, 2 H), 5.75–5.94 (m, 1 H).
13C NMR (CDCl3): d = 24.5, 25.8, 60.8, 67.8, 79.5, 80.2, 85.2,
105.2, 112.6, 117.3, 133.8.
MS: m/z (%) = 215 (21, [M – 15]+), 59 (100).
Allyl 2,3-O-Isopropylidene-5-O-methoxymethyl-a-D-ribofura-
noside (6)
Yield: 81%; colourless syrup; [a]D +82 (c = 1.5, CHCl3).
1H NMR (CDCl3): d = 1.36 (s, 3 H), 1.57 (s, 3 H), 3.36 (s, 3 H), 3.66
(d, J = 4.1 Hz, 2 H), 4.02–4.13 (m, 1 H), 4.23–4.36 (m, 2 H), 4.58–
4.62 (m, 1 H), 4.63 (s, 2 H), 4.65–4.70 (m, 1 H), 5.04 (d, J = 4.0 Hz,
1 H), 5.13–5.37 (m, 2 H), 5.85–6.04 (m, 1 H).
13C NMR (CDCl3): d = 25.8, 25.9, 55.2, 67.8, 68.9, 80.1, 80.7, 80.9,
96.6, 101.0, 115.1, 116.9, 134.2.
Anal. Calcd for C11H18O5: C, 57.38; H, 7.88. Found: C, 57.14; H,
8.11.
MS: m/z (%) = 259 (10, [M – 15]+), 59 (100).
Anal. Calcd for C13H22O6: C, 56.92; H, 8.08. Found: C, 57.12; H,
8.10.
Allyl 2,3-O-Isopropylidene-b-L-lyxofuranoside (20)
Colourless solid; mp 50 °C; [a]D –61 (c = 0.5, CHCl3).
Methyl 2,3-O-Isopropylidene-5-O-methoxymethyl-a-D-ribo-
furanoside (7)
Yield: 93%; colourless syrup; [a]D +76 (c = 1, CHCl3).
1H NMR (CDCl3): d = 1.33 (s, 3 H), 1.48 (s, 3 H), 3.63 (dd, J = 11.6,
6.0 Hz, 1 H), 3.70–3.78 (m, 2 H), 4.01 (br ddt, J = 12.7, 5.9, 1.1 Hz,
1 H), 4.11 (dd, J = 5.9, 2.6 Hz, 1 H), 4.16–4.25 (m, 2 H), 4.75 (d,
J = 2.5 Hz, 1H), 5.15–5.35 (m, 2 H), 5.80–5.95 (m, 1 H).
Synthesis 2004, No. 11, 1830–1834 © Thieme Stuttgart · New York