Reactions of 2-chloro-NN-diethyl-1,1,2-trifluoroethylamine with alcohols. Part 2. Bridgehead fluorination of gibberellins

Abstract

Four New Fluoro-gibberellins, viz. 2β,7α-difluoro-4aα-hydroxy-1β-methyl-8-methylenegibb-3-ene-1 α,10β-dicarboxylic acid 1,4a-lactone (4), 4β,7α-difluoro-4aα-hydroxy-1β-methyl-8-methylenegibb-2-ene-1α,10β-di-carboxylic acid 1,4a-lactone (7), and the 8-epimers of 7α-fluoro-4aα-hydroxy-1β,8-dimethylgibb-2-ene-1α,10β-dicarboxylic acid 1,4a-lactones[(18) and (19)] and of 7α-fluoro-4aα-hydroxy-1β,8-dimethylgibbane-1α,10β-dicarboxylic acid 1,4a-lactone [(12) and (13)], containing bridgehead fluorine atoms have been prepared by the fluorination of esters of gibberellins with the title reagent, followed by de-esterification.