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 photochemistry of peptide-derived benzoin esters is more efficient than that of furoin esters and is appropriate for the photolytic initiation of biochemical processes. Methodology to assess the enantiomeric purity of the resulting free peptide was developed and used to monitor the protection-deprotection chemistry. Synthesis based on alkylation of the cesium salt of the peptide proved more effective than DCCI-mediated chemistry on stereochemical grounds.