One Carbon Elongation of the Hajos-Parrish Ketone. Synthesis of (+)-(3aS,7aR)-Octahydro-3a-hydroxy-7a-methyl-1-methylene-5H-indene-5-one

Abstract
The dificulties encountered for the C-1 methylenation of Hajos-Parrish (1) and Hajos-Wiechert (2) ketones, were overcome by the use of Conia reaction on their C-5 dithiane derivatives.