PHOTOLABILE BENZOIN AND FUROIN ESTERS OF A BIOLOGICALLY-ACTIVE PEPTIDE

Benzoin and furoin esters of N-carbobenzyloxyglycylphenylalanine were prepared and photolyzed under a variety of conditions. The photochemis try of peptide-derived benzoin esters is more efficient than that of f uroin esters and is appropriate for the photolytic initiation of bioch emical processes. Methodology to assess the enantiomeric purity of the resulting free peptide was developed and used to monitor the protecti on-deprotection chemistry. Synthesis based on alkylation of the cesium salt of the peptide proved more effective than DCCI-mediated chemistr y on stereochemical grounds.