Synthesis of compounds related to gibberellins. Part I. Methyl 3-methoxy-6β-methyl-16-methylene-9αH-gibba-1(10),2,4-triene-4-carboxylate

Abstract

Terracinoic acid (4-carboxy-5-hydroxy-3-methyl-1-oxoindan-2-ylacetic acid)(I) has been elaborated, in a stereo-selective manner, to methyl 3-methoxy-6β-methyl-16-methylene-9αH-gibba-1(10),2,4-triene-4-carboxylate (XVI). An alternative method for removal of a C-12 carbonyl group in 12,16-dioxogibbanes involving selective reduction of the 16-oxo-function is reported.