NEW MATERIAL:A compound expressed by formula I (R1 is alkyl, aryloxyalkyl, aralkyl or aryl group; R2 is H or carboxyl-protecting group; R3 is halogen or hydroxyl group; R4 is H or alkoxy group).
USE: An intermediate for the synthesis of a 1-oxacephem compound useful as an antimicrobial agent.
PROCESS: Penicillin 1-oxide expressed by formula II, e.g. 6β-benzamidopenicillanic acid diphenylmethyl ester 1β-oxide, and triphenylphosphine are dissolved in a solvent, e.g. toluene, and an acid catalyst, e.g. squalic acid, is added to the resulting solution. The mixture is then subjected to ring opening and closure by heating, and the solvent is distilled off. Acetonitrile is added to the residue to precipitate and remove triphenylphosphine sulfide. Isopropyl alcohol is further added to deposit the objective compound as crystals.
KAMATA SUSUMU
NAGATA WATARU
| JPS5387388A | 1978-08-01 | |||
| JPS53105491A | 1978-09-13 |