Studies on intramolecular alkylation. VII. The preparation of phenanthrene derived tetracyclic ketones : Intermediates for gibberellin synthesis

Abstract

The 1,2,3,4,9,10-hexahydrophenanthrenecarboxylic acids (9), (10) and (12) have been prepared and converted via their diazomethylcarbonyl derivatives to the 1,2,3,9,10,10a-hexahydro-2,l0a-ethano- phenanthren-12-one derivatives (2), (3) and (4), respectively, by short and efficient routes.