The microbiological production of analogues of mould metabolites. Part I. Production of fluorogibberellic acid and fluorogibberellin A9 by Gibberella fujikuro

Abstract

1β-Fluoromethyl-10β-formyl-4aα-methyl-8-methylenegibbane-1α-carboxylic acid (3) and 1β-fluoromethyl-4aα-methyl-8-methylenegibbane-1α,10β-dicarboxylic acid (fluorogibberellin A₁₂)(4) have been prepared from 6α,7β,18-trihydroxykaur-16-en-19-oic acid 19,6-lactone (7). The aldehyde (3) was converted by G. fujikuroi into 1β-fluoromethyl-2β,4aα,7α-trihydroxy-8-methylenegibb-3-ene-1α,10β-dicarboxylic acid 1,4a-lactone (18) and 1β-fluoromethyl-4aα-hydroxy-8-methylenegibbane-1α,10β-dicarboxylic acid 1,4a-lactone (fluorogibberellin A₉)(15).