Studies related to penicillins. Part X. Some transformations of 4-iso-propylidene-3-oxo-7β-phenoxyacetamidocepham

Abstract

m-Chloroperbenzoic acid converts 4-isopropylidene-3-oxo-7β-phenoxyacetamidocepham (2) into a mixture of sulphoxides (10) and (11), which is then oxidised to the sulphone (3). 3-Hydroxy-4-isopropylidene-7β-Phen-oxyacetamidocepham (12), obtained by reduction of the cepham (2) with lithium hydridotri-t-butoxvaiuminate, affords a single sulphoxide sodium periodate. The cepham (2) is also converted into [(2R,3R)-1-(2-hvdroxy-2-methylpropionyl)-4-oxo-3-phenoxyacetamidoazetidin-2-ylthio]acetic acid (7) by potassium permanganate and into 4″,4″-dimethyl-7′β-phenoxyacetamidodispiro[oxiran-2,3′-cepham-4′,3″-Δ¹″-pyrazoline](19) by diazomethane.