Banerjee and Ghosh
CH2), 2.54 (1H, d, J ) 12 Hz, CH2), 2.62 (1H, s, OH), 3.78 (1H,
d, J ) 9 Hz, CH), 3.91 (1H, m, CH), 4.11 (2H, m, CH2), 4.45
(1H, d, J ) 6 Hz, CH), 4.76 (1H, s, dCH2), 4.94 (1H, s, dCH2),
5.66 (1H, d, J ) 6 Hz, CH); 13C NMR δ 24.2 (CH3), 25.2 (CH3),
26.3 (CH3), 26.5 (CH3), 26.6 (CH3), 39.6 (CH2), 67.8 (CH2), 72.9
(CH), 78.9 (C), 80.6 (CH), 82.4 (CH), 103.4 (CH), 109.5 (C),
112.4 (C), 115.0 (CH2), 141.8 (C). Anal. Calcd for C16H26O6: C,
61.13; H, 8.34. Found: C, 61.28; H, 8.51.
and concentrated to afford a colorless viscous liquid (400 mg).
This diol was converted to the alkene following the procedure
developed by Gregg and Samuelsson.27 To a solution of this
liquid in toluene (20 mL) was added imidazole (400 mg, 5.83
mmol) and PPh3 (1.52 g, 5.83 mmol). This mixture was refluxed
gently and iodine (1.11 g, 4.38 mmol) was added in small
portions. Refluxing was continued for 2 h. The reaction mixture
was cooled to room temperature and aqueous NaOH solution
(5 mL, 20%) was added to it. Usual workup of this mixture
followed by column chromatography using ether-petroleum
ether (1:19) as eluent afforded the diene 4a (230 mg, 60%) as
a colorless viscous liquid: [R]25D +51.7 (c 5.4, CHCl3); 1H NMR
δ 1.27 (3H, s, CH3), 1.52 (3H, s, CH3), 2.15 (1H, dd, J ) 7.3,
15.0 Hz), 2.47 (1H, dd, J ) 6.9, 15.0 Hz), 3.34 (3H, s, OMe),
4.33 (1H, d, J ) 3.6 Hz, C2-H), 4.50 (1H, d, J ) 6.3 Hz, C4-H),
5.03-5.09 (2H, m), 5.21-5.42 (2H, m), 5.57 (1H, d, J ) 3.6
Hz, C1-H), 5.75-5.86 (2H, m); 13C NMR δ 26.8 (CH3), 27.3
(CH3), 34.5 (CH2), 52.9 (OCH3), 82.4 (2CH), 84.4 (C), 103.8
(CH), 112.9 (C), 118.8 (CH2), 119.4 (CH2), 132.8 (CH), 132.9
(CH).
1:2,5:6-Di-O-isopropylidine-3-C-(2′-propenyl)-3-O-meth-
yl r-D-allofuranose 3a. To a magnetically stirred suspension
of NaH (130 mg, 2.7 mmol, 50% in oil), freed from adhering
oil by repeated washing with petroleum, in THF (5 mL) was
added dropwise a solution of the alcohol 2a (550 mg, 1.83
mmol) in THF (5 mL). The mixture was gently refluxed for 2
h and then cooled to room temperature. To it was added HMPA
(0.5 mL) followed by CH3I (0.3 mL, 3.6 mmol). After refluxing
for 2 h, the reaction mixture was cooled to room temperature
and quenched by adding saturated NH4Cl solution (2 mL).
Usual workup of the reaction mixture followed by column
chromatography using ether-petroleum ether (1:9) as eluent
1,2-Di-O-isopropylidine-3-C-(2′-propenyl)-3-O-benzyl-
4â-ethynyl-r-D-allofuranose 4b. Following the above pro-
cedure the diacetonide 3b (1.5 g, 3.84 mmol) was converted to
afforded the methyl ether 3a (520 mg, 90%) as a colorless
1
viscous liquid: [R]25 +20.0 (c 1.56, CHCl3); H NMR δ 1.29
D
(3H, s, CH3), 1.32 (3H, s, CH3), 1.39 (3H, s, CH3), 1.54 (3H, s,
CH3), 2.25 (1H, dd, J ) 7.5, 15.2 Hz), 2.63 (1H, dd, J ) 6.3,
15.2 Hz), 3.45 (3H, s, OMe), 3.84 (1H, d, J ) 2.7 Hz), 4.03-
4.09 (3H, m), 4.36 (1H, d, J ) 3.5 Hz, C2-H), 5.10-5.16 (2H,
m), 5.52 (1H, d, J ) 3.5 Hz, C1-H), 5.85-5.99 (1H, m); 13C
NMR δ 25.8 (CH3), 26.8 (CH3), 26.9 (CH3), 27.4 (CH3), 34.5
(CH2), 53.3 (OCH3), 68.8 (CH2), 73.1 (CH), 82.3 (CH), 83.5 (CH),
83.9 (C), 103.4 (CH), 110.0 (C), 113.0 (C), 119.0 (CH2), 137.7
(CH). Anal. Calcd for C16H26O6: C, 61.13; H, 8.34. Found: C,
61.51; H,8.32
the diene 4b (470 mg, 53%) as a colorless viscous liquid: [R]25
D
+13.6 (c 0.6, CHCl3); 1H NMR δ 1.35 (3H, s, CH3), 1.60 (3H, s,
CH3), 2.33 (1H, dd, J ) 7.2, 14.7 Hz, CH2), 2.56 (1H, dd, J )
7.2, 14.7 Hz, CH2), 4.49 (1H, d, J ) 3.9 Hz, C2H), 4.67 (2H, s,
PhCH), 5.15 (2H, m, dCH2), 5.27 (1H, d, J ) 10.8 Hz, dCH2),
5.43 (1H, d, J ) 16.2 Hz, dCH2), 5.69 (1H, d, J ) 3.9 Hz, CH
C
1-H), 5.85-5.96 (1H, m, dCH), 7.23-7.45 (5H, m, ArH); 13
C
NMR δ 27.0 (CH3), 27.3 (CH3), 36.3 (CH2), 67.2 (CH2), 82.2
(CH), 82.4 (CH), 84.7(C), 104.2 (CH), 112.9(C), 118.7 (CH2),
118.8 (CH2), 127.8 (CH), 128.8 (CH), 132.6 (CH), 132.8 (CH),
133.1 (CH), 139.2 (C). Anal. Calcd for C19H24O4: C, 72.12; H,
7.64. Found: C, 72.37; H, 7.21.
1:2,5:6-Di-O-isopropylidine-3-C-(2′-propenyl)-3-O-ben-
zyl-r-D-allofuranose 3b. Following the above procedure, the
alcohol 2a (800 mg, 2.66 mmol) was alkylated with BnBr (0.4
1,2-Di-O-isopropylidine-3-C-(2′-methyl-2′-propnyl)-3-O-
benzyl-4â-ethenyl -r-D-allofuranose 4c. Following the above
procedure the diacetonide 3c (1.8 g, 4.45 mmol) was converted
to the diene 4c (840 mg, 57%) as a colorless viscous liquid:
[R]21D +13.2 (c 0.93, CHCl3); 1H NMR δ 1.34 (3H, s, CH3), 1.61
(3H, s, CH3), 1.84 (3H, s, CH3), 2.15 (1H, d, J ) 15 Hz,), 2.50
(1H, d, J ) 15 Hz,), 4.60 (1H, d, J ) 3.6 Hz, C2-H), 4.70 (1H,
d, J ) 11.5 Hz, PhCH), 4.82 (4H, m), 5.26 (1H, d, J ) 10.65
Hz, dCH2), 5.37 (1H, dt, J ) 1.5, 17.2 Hz), 5.67 (1H, d, J )
3.6 Hz, C1-H), 5.82-5.93 (1H, m, dCH-), 7.20-7.37 (5H, m,
ArH); 13C NMR δ 24.4 (CH3), 26.50 (CH3), 26.9 (CH3), 37.6
(CH2), 66.5 (CH2), 80.7 (CH), 82.2 (CH), 84.2 (C), 103.1 (CH),
112.5 (C), 115.2 (CH2), 119.2 (CH2), 127.1 (CH), 127.2 (CH),
128.2 (CH), 132.5 (CH), 138.9 (C), 141.4 (C). Anal. Calcd for
C20H26O4: C, 72.70; H, 7.93. Found: C, 72.32; H, 8.16.
mL, 3.19 mmol) to afford the benzyl ether 3 (730 mg, 70%):
1
mp 98 °C; [R]25 +20.5 (c 3.7, CHCl3); H NMR δ 1.33 (3H, s,
D
CH3), 1.34 (3H, s, CH3), 1.37 (3H, s, CH3), 1.59 (3H, s, CH3),
2.41 (1H, dd, J ) 7.2, 14.8 Hz, CH2), 2.68 (1H, dd, J ) 6.7,
14.8 Hz, CH2), 3.95 (1H, m), 4.10 (1H, m), 4.22 (2H, m), 4.8
(1H, d, J ) 3.6 Hz, C2H), 4.72 (1H, d, J ) 11.1 Hz, PhCH),
4.84 (1H, d, J ) 11.1 Hz, PhCH), 5.15 (2H, m, CH2), 5.62 (1H,
d, J ) 3.6 Hz, C1H), 6.01 (1H, m, -CH)), 7.21-7.40 (5H, m,
ArH); 13C NMR δ 25.8 (CH3), 26.9 (CH3), 27.0 (CH3), 27.4 (CH3),
36.2 (CH2), 67.3 (CH2), 68.4 (CH2), 73.4 (CH), 81.7 (CH), 83.4
(CH), 84.0(C), 103.9 (CH), 109.9(C), 113.1(C), 119.0 (CH2),
127.5 (CH), 128.4 (CH), 133.0 (CH), 139.6(C). Anal. Calcd for
C22H30O6: C, 67.67; H, 7.74. Found: C, 68.02; H, 7.24.
1:2,5:6-Di-O-isopropylidine-3-C-(2′-methyl-2′-proprenyl)-
3-O-benzyl-r-D-allofuranose 3c. Following the above pro-
cedure, the alcohol 2b (850 mg, 2.70 mmol) was alkylated with
BnBr (0.4 mL, 3.24 mmol) to afford the benzyl ether 3c (870
Photocycloaddition of the Dienes. cis-syn-cis-4r,5r-
Di-O-isopropylidine-6r-methoxy-3-oxatricyclo[3.2.0.02,6]-
decane 5a. A magnetically stirred solution of the diene 4a
(110 mg, 0.46 mmol) in dry ether (150 mL) containing CuOTf
(10 mg, 0.03 mmol) under an argon atmosphere was irradiated
with a 450 W medium-pressure mercury vapor lamp (Hanovia)
through a double-walled water-cooled quartz immersion well
for 3.5 h. The reaction mixture was then washed successively
with ice-cold NH4OH (35%, 3 × 10 mL) and water (2 × 10 mL)
and dried. After evaporation of the solvent the residual mass
was chromatographed using ether-petroleum ether (1:19) as
mg, 80%) as a colorless viscous liquid: [R]25 +14.5 (c 0.57,
D
1
CHCl3); H NMR δ 1.34 (9H, s, CH3), 1.61 (3H, s, CH3), 1.88
(3H, s, CH3), 2.17 (1H, d, J ) 15 Hz, CH2), 2.67 (1H, d, J ) 15
Hz, CH2), 3.94 (1H, m), 4.16 (2H, m), 4.36 (1H, d, J ) 6 Hz,
CH), 4.62 (1H, d, J ) 3.0 Hz, C2-H), 4.77 (1H, d, J ) 12 Hz,
PhCH), 4.90 (2H, d, J ) 18 Hz, dCH2), 5.05 (1H, d, J ) 12
Hz, PhCH), 5.61 (1H, d, J ) 6 Hz, C1-H), 7.23-7.39 (5H, m,
ArH); 13C NMR δ 24.3 (CH3), 25.2 (CH3), 26.2 (CH3), 26.4 (CH3),
27.0 (CH3), 38.5 (CH2), 67.1 (CH2), 68.4 (CH2), 72.5 (CH), 80.3
(CH), 83.1 (CH), 83.4 (C), 102.0 (CH), 109.5 (C), 112.6 (C), 115.1
(CH2), 127.0 (CH), 127.3 (CH), 128.1 (CH), 139.3 (C), 141.4
(C). Anal. Calcd for C23H32O6: C, 68.29; H, 9.79. Found: C,
68.02; H, 8.01.
1,2-Di-O-isopropylidine-3-C-(2′-propenyl)-3-O-methyl-
4â-ethynyl-r-D-allofuranose 4a. A solution of the diacet-
onide 3a (500 mg, 1.59 mmol) in aqueous acetic acid (5 mL,
75%) was stirred at room temperature for 12 h. The reaction
mixture was diluted with ethyl acetate (30 mL) and washed
repeatedly with saturated aqueous NaHCO3 solution (5 × 3
mL) to make it free from acid. The organic layer was dried
eluent to afford the cyclobutane derivative 5a (80 mg, 73%)
1
as a colorless viscous liquid: [R]25 +35.4 (c 1.05, CHCl3); H
D
NMR δ 1.37 (3H, s, CH3), 1.59 (3H, s, CH3), 1.93-2.38 (6H,
m), 2.87 (2H, m), 3.32 (3H, s, OCH3), 4.38 (1H, d, J ) 5.1 Hz,
C
C
2-H), 4.52 (1H, d, J ) 3.9 Hz, C5-H), 5.94 (1H, d, J ) 3.6 Hz,
4-H); 13C NMR δ 16.6 (CH2), 26.6 (CH3), 26.9 (CH2), 27.1
(CH3), 37.5 (CH2), 38.5 (CH), 41.0 (CH), 52.3 (OCH3), 80.4 (CH),
86.4 (CH), 98.1 (C), 106.0 (CH), 112.5 (C). Anal. Calcd for
C13H20O4: C, 64.96; H, 8.39. Found: C, 64.88; H, 8.51.
(27) Gregg, P. J.; Samuelsson, B. Synthesis 1979, 469.
3986 J. Org. Chem., Vol. 68, No. 10, 2003