Abstract
Chemical synthesis of a trachylobagibberellin analogue - 3-hydroxy- δ1.10−12, 16-cyclogibberellin dimethyl ester 4 from gibberellin acid GA3 3 was described herein. The key step is the decomposition of the tosylhydrazone 11 to construct the novel [3.2.1.0.2.7] octane system.