Synthesis of α-Amino-cycloheptatriene-1-acetic Acids and Their 7-Acylaminocephalosporin Derivatives

Abstract

tert-Butyl α-amino-2, 4, 6-cycloheptatriene-1-acetate (6) was prepared by treatment of tert-butyl N-benzylideneglycinate (5) with n-butyllithium followed by reaction with tropylium tetrafluoroborate. Heating 6 in xylene resulted in isomerization to tert-butyl α-amino-1, 3, 6-cycloheptatriene-1-acetate (7). Both the glycine derivatives were utilized for the acylation of a 7-amino-3-deacetoxycephalosporanic acid (7-ADCA) derivative (10) to obtain the orally active acyl derivative (14).