Synthesis of substances related to gibberellins—XXI

Gibberellins: Structure and Metabolism

“…In vitro synthesis.-As the culmination of extended preparatory work, th laboratory of Y. Sumiki has recently succeeded in the total synthesis of GA2, GA4, GA9, and GA10 (racemic forms), starting with o-xylene and pro ceeding through epigibberic acid and gibberellin C as major intermediates (58). Whether GAs thus synthesized will be widely used in biological research remains to be seen; the procedure is a rather complex one.…”

Introduction—Biofunctional Molecules and Organic Synthesis

“…In 1938, Yabuta and Sumiki isolated the plant hormone gibberellins as crude crystals, which elongated rice seedlings. 11 As to the biosynthesis, biodegradation and mode of action of the gibberellins, chemists and biologist have been involved for many years. 4 With the established structure of a biofunctional molecule, one can proceed with further chemical or biological research.…”

Synthesis of Phytohormones, Phytoalexins and Other Biofunctional Molecules of Plant Origin

“…Reduction of the Figure 2. 24,25 Gibberellin C with plant-growth-promoting activity was thus synthesized from B. Modified by permission of Shokabo Publishing Co., Ltd aromatic A-ring of A to give B must be feasible.…”

“…After extensive experimentation, 26 the conversion could be achieved as shown in Figure 2.9. 25,27,28 Classical electrophilic nitration of methyl epigibberate was followed by reduction and diazotization, and the resultant diazonium salt was hydrolysed to give phenol A. Hydrogenation of the phenol ring over RhO 2 /PtO 2 in acetic acid was followed by oxidation to give diketo ester C, which gave unsaturated diketo ester D after 4 steps.…”