New intermediates in the aqueous decomposition of gibberellic acid

Abstract

The decomposition pathway of gibberellic acid (I) through gibberellenic acid (III) in aqueous solution has been investigated. Decomposition of gibberellenic acid in deuterium oxide gives [9-²H]allogibberic acid (V), [9-²H]-9-epi-allogibberic acid (VI), and unlabelled 9,11-didehydroallogibberic acid (IX). Two partially characterised hydroperoxides (XV) and (XVII) have been detected as intermediates in the oxidative transformation of gibberellic acid through gibberellenic acid to 9,11-didehydroallogibberic acid. Mechanisms are proposed on the basis of these results.