derivatives of 7 oxo acid 1 azabiciclo 3.2.0 epta 2 and 2 carboxylic particularly useful as antibiotics and process for their preparation

摘要

7-Oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid derivatives of formula (I): IMAGE (I) (in which:) R1 represents a hydrogen atom or an optionally substituted alkyl group; X represents an oxy group, a thio group, a sulphinyl group or a sulphonyl group; A represents a bivalent for trivalent saturated aliphatic hydrocarbon group; p is 1 (when A is bivalent) or 2 (when A is trivalent); R2 represents an azido, nitro or cyano group or one of the groups of formula IMAGE m and n are the same or different and each is 0 or 1; R represents an amidino group or a group of formula R4, -N(R4)2 or -YR4, B represents a group of formula IMAGE D represents a group of formula IMAGE (provided that, where m and n are both 1, the groups represented by B and D must be different); R4 represents a hydrogen atom or an alkyl group and, where there are 2 or more groups represented by R4, they may be the same or different, and Y represents an oxygen atom or a sulphur atom; and R3 represents a carboxy group or a protected carboxy group) and pharmaceutically acceptable salts thereof are valuable antibiotics and may be prepared by a process which includes heating a corresponding phosphorus-ylide compound.