Synthetic studies toward complex diterpenoids. Stereocontrolled total synthesis of some gibbane synthons and degradation products of gibberellins

UR Ghatak, PC Chakraborti

Index: Ghatak,U.R.; Chakraborti,P.C. Journal of Organic Chemistry, 1979 , vol. 44, # 25 p. 4562 - 4566

Full Text: HTML

Citation Number: 0

Abstract

15b, are described. The key intermediates, 1, 2, 3, 4-tetrahydro-8-methylfluorene-2- carboxylic acid (6a) and its 2-methyl analogue 6b, prepared by cycloaddition reactions, are converted into the corresponding a'-diazomethyl ketones lla and llb and are subjected to intramolecular ketocarbenoid addition and boron trifluoride-ethercatalyzed cyclization leading to cyclopropyl ketones 12a, b and A9J1-gibbenes 13a, b, respectively. Catalytic ...