AMINO ACID DERIVATIVES AND THEIR PRODUCTION AND USE IN PREPARING CARBAPENEM AND CARBAPENAM COMPOUNDS

摘要

Novel amino acid derivatives of the formula wherein R<1> is a protecting group removable under reducing or acid conditions, and R<2> and R<5> are hydrogen or carboxylic protecting groups, are useful as intermediates in preparing stereospecific carbapenam/carbapenem derivatives. R<1> is removed under reducing conditions to form a pyrrolidine derivative, which is further cyclised from the R<5>=H compound to form a beta -lactam ring. Stereospecificity at the 6-position is achieved by treatment with lithium di-isopropylamide (LDA) and quenching at different temperatures. Compound (I) can be prepared by treating R<1>-protected R<3>-pyrrolidone carboxylic acid R<2>-ester with a lithium enolate of the formula R<4>CHLiCO2R<5>. The lithium enolate can be formed from R<4>CH2CO2R<5> by treatment with LDA.