The synthesis of 2,2-dialkylgibberellins

Abstract
An improved synthesis of 2,2-dimethylgibberellin A4(3), the highly active plant growth promoter, is described. The methods used were adapted to the synthesis of both radio- and stable-isotope labelled (3). The route was applied, with limited success, to the synthesis of 2,2-diethylgibberellin A4(6). Incubation of 2,2-dimethylgibberellin A4(3) with cultures of Gibberella fujikuroi, mutant B1 -41a, gave 2,2-dimethylgibberellin A1(20) on a preparative scale.