Sporidesmins. Part VII. Oxindoles derived from sporidesmin-B

Abstract

Anhydrosporidesmin-B when treated with boron trifluoride ether complex gave a biologically active oxindole named isosporidesmin-B. When isosporidesmin-B was treated with triethylamine in benzene the disulphide bridge was eliminated and the physical and chemical properties of the product suggested that its structure was 5-chloro-6,7-dimethoxy-1-methyloxindolidene-3-(1′,6′-dihydro-3′-hydroxy-1′,2′-dimethyl-6′-oxopyrazine-5′)-methine.