11.1 and 3.5, major CHHOSi), 3.78 (0.29 H, dd, J 11.3 and 3.3,
minor CHHOSi), 3.82 (0.71 H, dd, J 11.1 and 3.9, major
CHHOSi), 3.83 (0.29 H, dd, J 11.3 and 3.4, minor CHHOSi),
3.98 (0.29 H, s, minor OH), 4.16 (0.29 H, q, J 3.7, minor OCH-
CH2OSi), 4.18 (0.71 H, s, major OH), 4.21 (0.71 H, dt, J 1.5 and
3.6, major OCHCH2OSi), 4.48 (0.29 H, d, J 7.2, minor
CHORCO), 4.51 (0.71 H, d, J 5.8, major CHORCO), 4.80 (0.71
H, dd, J 5.8 and 1.5, major CHORCHORCH2OSi), 4.83 (0.29
H, dd, J 7.2 and 4.1, minor CHORCHORCH2OSi), 5.12–5.23
OH), 3.60–3.70 (2 H, m, CH2OH), 3.84 (1 H, d, J 11.0, OH),
3.95–4.00 (1 H, m, CHOH), 3.97 (1 H, d, J 2.0, CHOR), 4.04–
4.10 (1 H, m, CHOH), 4.11 (1 H, dd, J 5.5 and 2.0, CHOR),
5.10–5.18 (2 H, m, CH᎐CH ) and 5.84 (1 H, ddt, J 17.2, 10.1
᎐
2
and 7.1, CH᎐CH ); δ (22.5 MHz) 25.12 (Me), 27.38 (Me), 39.74
᎐
2
C
(CH CH᎐), 64.44 (CH OH), 68.17, 69.63, 77.00, 78.22 (4 C,
᎐
2
2
2 × CHOH, 2 × CHOR), 108.18 (CMe ), 117.84 (CH᎐CH )
᎐
2
2
and 134.58 (CH᎐CH ) (Found: C, 56.56; H, 8.69. C H O
᎐
2
11 20
5
requires C, 56.88; H, 8.68%).
(2 H, m, CH᎐CH ), 5.83–5.93 (0.29 H, m, minor CH᎐CH ),
᎐
᎐
2
2
6.01 (0.71 H, ddt, J 17.2, 10.2 and 7.1, major CH᎐CH ), 7.35–
7.47 (6 H, m, m- and p-H Ph) and 7.63–7.90 (4 H, m, o-H Ph);
δC(22.5 MHz) (major, β anomer) 19.15 (CMe3), 25.24 (Me),
5,6,7-Trideoxy-2,3-O-isopropylidene-á,â-D-lyxo-6-enofuranose 7
The triol 5 (1.00 g, 4.31 mmol) was dissolved in water (25 cm3)
and sodium periodate (1.20 g, 5.6 mmol) was added. The solu-
tion was stirred at room temperature for 2 h, and extracted with
ethyl acetate (3 × 80 cm3). The combined organic extracts were
dried (Na2SO4), and evaporated under reduced pressure. The
residue was purified by flash chromatography on silica gel with
25% diethyl ether in light petroleum as eluent to give the hemi-
acetal 7 (794.5 mg, 92%) as an oil, [α]D ϩ15.9 (c 1.48, CHCl3);
νmax(film)/cmϪ1 3420 (OH), 3079 (C᎐CH ), 2983, 2940, 1643
᎐
2
26.91 (4 C, Me, CMe ), 39.83 (CH C᎐), 65.52 (CH OSi), 82.02,
᎐
3
2
2
86.13, 86.94 (3 C, 3 × CHOR), 106.93 (anomeric C), 112.51
(CMe ), 118.48 (CH᎐CH ), 127.96 (4 C, Ph), 130.05 (C, Ph),
᎐
2
2
130.20 (C, Ph), 132.14 (C, Ph), 132.20 (C, Ph), 132.92
(CH᎐CH ) and 135.63 (4 C, Ph); (minor, α anomer) 19.27
᎐
2
(CMe ), 25.00 (Me), 26.64 (4 C, Me, CMe ), 43.65 (CH C᎐),
᎐
2
3
3
63.52 (CH2OSi), 81.00, 81.87, 82.37 (3 C, 3 × CHOR), 102.57
᎐
2
(anomeric C), 115.49 (CMe ), 118.74 (CH᎐CH ), 127.75 (4 C,
(C᎐C), 1434, 1375, 1210, 1164, 1063 and 1013; δ (400 MHz)
᎐
᎐
2
2
H
Ph), 129.82 (2 C, Ph), 132.74 (CH᎐CH ), 133.12 (C, Ph), 133.27
(C, Ph) and 135.75 (4 C, Ph) (Found: C, 69.13; H, 7.80.
(mixture of anomers, α:β = 7.5:1) 1.31 (2.64 H, s, major
Me), 1.36 (0.36 H, s, minor Me), 1.46 (2.64 H, s, major Me),
᎐
2
C27H36O5Si requires C, 69.20; H, 7.74%).
1.53 (0.36 H, s, minor Me), 2.45–2.49 (2 H, m, CH CH᎐),
᎐
2
2.58 (0.88 H, d, J 2.4, major OH), 3.51 (0.12 H, dt, J 3.2 and
7.0, minor OCHCH2), 3.86 (0.12 H, d, J 12.2, minor OH),
4.18 (0.88 H, dt, J 3.6 and 7.0, major OCHCH2), 4.48 (0.12
H, dd, J 6.0 and 3.5, minor CHORCHOH), 4.589 (0.12 H,
dd, J 6.0 and 3.2, minor CHORHCH2), 4.593 (0.88 H, d, J
5.9, major CHORCHOH), 4.67 (0.88 H, dd, J 5.9 and 3.6,
major CHORCHCH2), 4.94 (0.12 H, dd, J 12.2 and 3.5,
8-O-(tert-Butyldiphenylsilyl)-1,2,3-trideoxy-5,6-O-isopropyl-
idene-D-altro-oct-1-enitol 22
The lactol 21 (2.88 g, 6.15 mmol) was dissolved in dry toluene
(100 cm3), and the solution was cooled to Ϫ78 ЊC. DIBAL
(1.5 in toluene; 41 cm3, 61.5 mmol) was added dropwise and
the reaction mixture was stirred at Ϫ78 ЊC for 3 h. The reaction
was quenched by careful addition of aq. hydrochloric acid
(2 M; 150 cm3), and extracted with ethyl acetate (3 × 200 cm3).
The extracts were dried (Na2SO4), and evaporated under
reduced pressure to leave a residue, which was purified on silica
gel with 25% diethyl ether in light petroleum as eluent to give
the recovered starting material (0.76 g, 26% recovery) and the
diol 22 (1.87 g, 88% based on consumed starting material) as
an oil, [α]D Ϫ4.6 (c 1.41, CHCl3); νmax(film)/cmϪ1 3441 (OH),
minor OCHOH), 5.06–5.20 (2 H, m, CH᎐CH ), 5.35 (0.88 H,
᎐
2
d, J 2.4, major OCHOH), 5.80–5.89 (0.12 H, m, minor
CH᎐CH ) and 5.87 (0.88 H, ddt, J 17.1, 10.2 and 6.9, major
᎐
2
CH᎐CH ); δ (22.5 MHz) (major, α anomer) 24.79 (Me),
᎐
2
C
25.92 (Me), 32.79 (CH C᎐), 79.48, 80.10, 85.53 (3 C,
᎐
2
3 × CHOR), 100.66 (OCHOH), 112.27 (CMe2), 117.04
(CH᎐CH ) and 134.19 (CH᎐CH ); (minor, β anomer) 24.79
᎐
᎐
2
2
(Me), 25.65 (Me), 32.49 (CH C᎐), 75.39, 78.61, 79.89 (3 C,
᎐
2
3072 (C᎐CH ), 3050, 2983, 2932, 2858, 1642 (C᎐C), 1590,
3 × CHOR), 96.51 (OCHOH), 112.89 (CMe2), 117.31
᎐
᎐
2
1472, 1428, 1381, 1215, 1113 and 1062; δH (400 MHz) 1.07 (9
(CH᎐CH ) and 133.81 (CH᎐CH ) (Found: C, 59.63; H, 8.13.
᎐ ᎐
2 2
H, s, CMe3), 1.32 (3 H, s, Me), 1.37 (3 H, s, Me), 2.36–
C10H16O4 requires C, 59.98; H, 8.05%).
2.41 (2 H, m, CH CH᎐), 2.48 (1 H, d, J 6.7, OH), 2.89 (1 H,
᎐
2
d, J 4.5, OH), 3.77 (1 H, dd, J 10.3 and 5.2, CHHOSi), 3.88
(1 H, dd, J 10.3 and 2.4, CHHOSi), 4.06–4.13 (4 H, m,
(3aS,5R,6S,7R,7aS)-Octahydro-5-hydroxy-6,7-isopropylidene-
dioxy-1-methyl-2,1-benzisoxazole 11
2 × CHOR, 2 × CHOH), 5.09–5.17 (2 H, m, CH᎐CH ), 5.89
The hemiacetal 7 (591.3 mg, 2.95 mmol) and N-methyl-
hydroxylamine hydrochloride (2.47 g, 29.5 mmol) were dis-
solved in dry pyridine (25 cm3), and the solution was stirred at
room temperature for 20 h, after which the pyridine was evap-
orated off and the residue was co-evaporated with toluene
under reduced pressure. The residue was partitioned between
water (100 cm3) and ethyl acetate (3 × 120 cm3). The combined
organic extracts were dried (Na2SO4), and evaporated under
reduced pressure. The residue was passed through a short
column of silica gel with light petroleum–diethyl ether (1:2) as
eluent to give the nitrone 9 (676.3 mg, 100%) as a crystalline
solid, which was then dissolved in dry toluene (100 cm3) and the
solution was refluxed for 18 h. The toluene was removed under
reduced pressure and the residue was purified by flash chrom-
atography on silica gel with diethyl ether as eluent to afford the
isoxazolidine 11 (640.3 mg, 95%) as an oil, [α]D Ϫ115.6 (c 1.45,
CHCl3); νmax(film)/cmϪ1 3419 (OH), 2987, 2936, 2879, 1457,
1380, 1244, 1214, 1164, 1058 and 1012; δH (400 MHz) 1.33 (3 H,
s, Me), 1.45 (3 H, s, Me), 1.58 (1 H, ddd, J 14.2, 6.5 and 3.6,
CHHCHOH), 2.00 (1 H, ddd, J 14.2, 7.7 and 2.9, CHH-
CHOH), 2.73 (3 H, s, NMe), 2.87–2.94 (2 H, m, NCH,
CHCH2ON), 3.73 (2 H, dd, J 8.1 and 4.2, CH2ON), 4.17–4.23
(2 H, m, CHOH, CHOR), 4.29 (1 H, dd, J 7.2 and 2.3, CHOR)
and 4.34 (1 H, br s, OH); δC(22.5 MHz) 24.10 (Me), 26.73 (Me),
29.47 (CH2CHOH), 37.71 (CHCH2), 43.65 (NMe), 67.90,
᎐
2
(1 H, ddt, J 17.2, 10.1 and 7.1, CH᎐CH ), 7.36–7.46 (6 H, m,
᎐
2
m- and p-H Ph) and 7.65–7.69 (4 H, m, o-H Ph); δC(22.5
MHz) 19.21 (CMe3), 24.88 (Me), 26.82 (3 C, CMe3), 27.09
(Me), 39.44 (CH C᎐), 65.43 (CH OSi), 68.20, 69.46, 76.41,
᎐
2
2
78.71 (4 C, 2 × CHOR, 2 × CHOH), 108.06 (CMe2), 117.31
(CH᎐CH ), 127.72 (4 C, Ph), 129.78 (2 C, Ph), 132.92 (C,
᎐
2
Ph), 132.98 (C, Ph), 134.94 (CH᎐CH ) and 135.51 (4 C, Ph)
᎐
2
(Found: C, 68.64; H, 8.30. C27H38O5Si requires C, 68.90; H,
8.14%).
1,2,3-Trideoxy-5,6-O-isopropylidene-D-altro-oct-1-enitol 5
The diol 22 (608.8 mg, 1.29 mmol) was dissolved in dry THF
(50 cm3) and tetrabutylammonium fluoride (TBAF) (1.0 M in
THF; 3.23 cm3, 3.23 mmol) was added. The solution was stirred
at room temperature for 10 h, and then was evaporated under
reduced pressure to leave a residue, which was partitioned
between water (100 cm3) and ethyl acetate (3 × 100 cm3). The
organic layers were combined, dried (Na2SO4) and evaporated.
Flash chromatography of the residue on silica gel with diethyl
ether as eluent afforded the title compound 5 (214.4 mg, 72%) as
an oil, [α]D ϩ9.6 (c 1.66, CHCl3); νmax(film)/cmϪ1 3384 (OH),
3077 (C᎐CH ), 2984, 2936, 1642 (C᎐C), 1434, 1382, 1244, 1217,
᎐
᎐
2
1166 and 1062; δH (400 MHz) 1.33 (3 H, s, Me), 1.45 (3 H, s,
Me), 2.36–2.48 (3 H, m, CH CH᎐, OH), 2.60 (1 H, d, J 8.1,
᎐
2
1812
J. Chem. Soc., Perkin Trans. 1, 1997