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Tortajada, Mestres, and Iglesias-Arteaga
(2H, t, J ¼ 6.6 Hz, CH2OAc); 3.5 (2H, t, J ¼ 6.6 Hz, CH2OH); 1.94 (3H,
s, CH3COO); 1.5 (6H, m, (CH2)3).
5-Acetoxypentanal 3: PCC (1.044 g, 4.8 mmol) was added to a
solution of 1,5-pentanediol monoacetate 2 (472 mg, 3.2 mmol) in
CHCl3 (25 mL) and the mixture was stirred for 4 h. The reaction mixture
filtered through a chromatographic column packed with silica gel (10 g)
(eluted with hexane/ethyl acetate, 3/2.) and the solvent evaporated to
afford pure 5-acetoxypentanal 3 (439 mg, 3.0 mmol, 94%) as a colorless
liquid. Elemental analysis: Estimated for C7H12O3: C, 58.32%; H, 8.39%.
Found: C, 58.11%; H, 8.48%. IR (cmꢂ1): 2959 (ꢀCsp3–H); 1741 (ꢀC¼O
carboxyl); 1710 (ꢀC¼O carbonyl) 1245, 1044 (ꢀC–O). 1H NMR (ꢁ, ppm):
9.76 (1H, t, J ¼ 1.7 Hz, CHO); 4.03 (2H, t, J ¼ 6.6 Hz, CH2OAc); 2.35
(2H, t, J ¼ 6.9 Hz, CH2CHO); 2.01 (3H, s, CH3COO); 1.64 (6H, m, (CH2)3).
(Z )-5-Decenyl acetate 4: NaH (80 mg, 3.3 mmol, 1.1 equiv.) was
added to dry DMSO (5 mL). The mixture was stirred under argon at
60ꢀC until total dissolution of NaH, dry THF (15 mL) was added and
the mixture cooled to 10ꢀC. Pentyltriphenylphoshonium bromide
(438 mg, 3.3 mmol, 1.1 equiv.) was added under vigorous stirring and
the temperature was allowed to rise to 25ꢀC. After a brilliant red
colour developed the mixture was cooled to 0ꢀC and a solution of 5-acet-
oxypentanal 3 (438 mg, 3.0 mmol, 1 eq.) in dry THF (10 mL) was added.
Stirring was continued for 24 h. The resulting suspension was poured into
saturated NaCl solution (50 mL), filtered and extracted with diethyl ether
(2 ꢁ 30 mL). The combined extracts were washed with brine (2 ꢁ 25 mL),
dried (MgSO4), evaporated and the resulting residue was purified by flash
chromatography (hexane/ethyl acetate, 9/1) in silica gel to afford (Z)-5-
decenyl acetate 4 (389 mg, 1.9 mmol, 65%) as a pale yellow liquid.
Elemental analysis: Estimated for C12H22O2: C, 72.68%; H, 11.18%.
Found: C, 72.49%; H, 11.27%. IR (cmꢂ1): 3005 (ꢀCsp2–H); 2957, 2860
1
(ꢀCsp3–H); 1742 (ꢀC¼O); 1240, 1040 (ꢀC–O). H NMR (ꢁ, ppm): 5.33
(2H, dt, J1 ¼ 6 Hz, J2 ¼ 2.1 Hz CH¼CH); 4.03 (2H, t, J ¼ 6.6 Hz,
CH2OAc); 2.00 (7H, m, CH2CH¼CHCH2, CH3COO); 1.3 (2H, m,
CH2); 1.3 (6H, m, (CH2)2); 0.9 (3H, m, CH3).
(Z )-5-Decenol 5: KOH (112 mg, 2 mmol) was added to a solution of
(Z )-5-decenyl acetate 4 (157 mg, 0.79 mmol) in methanol (5 mL), the
mixture was stirred for 24 h, NaCl saturated solution (2 mL) was added
and methanol was eliminated under reduced pressure. The residue was
extracted with ethyl acetate (40 mL) and the organic layer washed with
3% HCl solution (2 ꢁ 15 mL) and brine (2 ꢁ 15 mL), dried (MgSO4) and
evaporated to afford pure (Z )-5-decenol 5 (119 mg, 0.77 mmol, 93%) after
flash chromatographic purification (hexane/ethyl acetate, 9/1). Elemental
analysis: Estimated for C10H20O: C, 76.86%; H, 12.90%. Found: C,