The chemistry of pseudomonic acid. Part 5. Structure and chemistry of pseudomonic acid C. X-Ray crystal structure of ethyl monate C

Abstract
A third and minor antibiotic component, designated pseudomonic acid C (1a),2 has been isolated from cultures of the strain Pseudomonas fluorescens NCIB 10586 which produced the structurally related pseudomonic acid A (2a) and B (3). The structure and stereochemistry of the acid (1a) have been confirmed by single-crystal X-ray analysis of the derived ethyl monate C (1f). Pseudomonic acid A has been converted stereospecifically into pseudomonic acid C in high yield. The epoxidation and the acid- and base-stability of pseudomonic acid C have been studied.