BENGAZOLES C-G FROM THE SPONGE JASPIS SP SYNTHESIS OF THE SIDE-CHAIN AND DETERMINATION OF ABSOLUTE-CONFIGURATION

Five new antifungal bengazoles (C-G) were isolated and fully character ized from a marine sponge of the genus Jaspis sp. Bengazoles- C-G, tog ether with the known bengazoles A and B, comprise a bomologous series of n, iso, and anteiso fatty acid esters (C-13-C-16) Of the same heter ocyclic bis-(oxazolyl)methanol parent. The complete relative and absol ute configurations of the bengazoles were determined by application of the modified Mosher method and interpretation of exciton coupling in the CD spectra of the tetra-p-bromobenzoate derivatives of bengazole A and that of a model tetrol synthesized in seven steps from L-fucose.