West African timbers. Part XVII. Correlation of gedunin, methyl angolensate, and andirobin
Abstract
Methyl angolensate has been converted into anhydroangolensic acid, the methyl ester of which is identical with deoxyandirobin. On partial hydrogenation, anhydroangolensic acid gave an isodihydro-compound, also obtained from gedunin by base-treatment of 7-deacetoxy-7-oxo-14,15-deoxygedunin. Since the structure of gedunin has been established by X-ray analysis this correlation proves the structures previously proposed for methyl angolensate and andirobin.