Isolation and Characterization of a Free Gibberellin and Glucosyl Esters of Gibberellins in Mature Seeds of Phaseolus vulgaris

Treatment of N⁶,N⁶,5′-O-tribenzoyl-2′,3′-O-isopropylidenetubercidin (VI) with aqueous acetic acid afforded N⁶,5′-O-dibenzoyltubercidin (V), which was mesylated to yield the dimesylate X. On treatment of X with sodium iodide and zinc dust, the 2′,3′-unsaturated derivatives of tubercidin XI and XIII were obtained.

N⁶,5′-O-Dibenzoyltubercidin 2′,3′-thionocarbonate (XIV), prepared from V by treatment with Corey-Winter reagent, was converted to the 1-methyl-2′,3′-unsaturated derivative XV in refluxing trimethyl phosphite.