Acetaldehyde → HCID 131711217, compound

Participants

Reaction Steps

A solution of acetaldehyde (20 ml., 354 mmole) and benzoic acid (73 mg., 0.6 mmole) in dry methylene chloride (50 ml.) as stirred at 23° and treated, over 30 minutes, with diphenylmethyl 3-(triphenylphosphoranylidenemethyl)-7β-(2-thienylacetamido)ceph-3-em-4-carboxylate (1.528 g., 2 mmoles). After stirring for a further 4 hours, the solvent was removed in vacuo, the residue was extracted with ethyl acetate (50 ml.) and the insoluble material was filtered off; the filtrate was washed with saturated sodium bicarbonate (50 ml.), water (50 ml.) and brine (50 ml.), and dried and evaporated to a foam (1.58 g.). This material was purified by chromatography on 0.05-0.2mm. Kieselgel with benzene: ethyl acetate = 10:1 as eluent. Combination of similar fractions (as judged by t.l.c.) gave pale-yellow crystals of the title compound (178 mg., 17%), Rf 0.58, m.p. 144° to 148° (decomp.), [α]D -25.9° (CHCl3), λmax. 286.5 nm. (ε 7,900), with an inflexion at 237 nm. (ε 13,200); the p.m.r. spectrum indicated that the compound was mainly the cis-isomer (with 5-10% trans) with signals at τ 3.96 (--CH=CHCH3, d, J 12 Hz.), 4.51 (=CHCH3, dd, J 12 and 7 Hz.) and 8.61 (CH=CHCH3, methyl dd, J 7 and 0.5 Hz.) [Found: C, 65.2; H, 5.0; N, 5.2; S, 11.9; C29H26N2O4S2 (530.7) requires C, 65.6; H, 4.9; N, 5.3; S, 12.1%].

Provenance & Evidence