22. Unprecedented ring contractions in cytochalasans: Formation of [10]cytochalasans and a cyclohepta[4,5]benz[1,2-d]isoindole derivative

Article abstract of DOI:10.1002/hlca.19950780203

A series of transformations of cytochalasin D (1; zygosporin A) was carried out. After treatment of the diol 7 with mesyl chloride and pyridine, and subsequent chromatography on silica gel, the 17-acetyl derivatives 12 and 13, the first members of the hitherto unknown [10]cytochalasans, were obtained. The alcohol 8 was converted to the chlorosulfinate 18 under the same conditions. Replacement of pyridine by triethylamine in the mesylation reaction led to the cyclohepta[4,5]benz[1,2-d]isoindole derivative 20, also representing a novel ring system.