Synthesis and Determination of the Absolute Configuration of Pyrenophorin and Vermiculin

Abstract

Two macrocyclic dilactides, the fungicide pyrenophorin (1) and the antibiotic vermiculin (2), have now been prepared in optically active form by use of the dithiane method. Their synthesis also proves that natural (1) has the (R,R) configuration and natural (2) the (S,S) configuration.