Studies on the Total Synthesis of dl-Colchiceine. I. Synthesis of 3-Hydroxy-9, 10, 11-trimethoxy-1, 2, 3, 4, 6, 7-hexahydro-5H-dibenzo [a, c] cycloheptatrien-5-one.

Abstract

3-Hydroxy-9, 10, 11-trimethoxy-1, 2, 3, 4, 6, 7-hexahydro-5H-dibenzo [a, c] cycloheptatrien-5-one (XX) was synthesized from ethyl 2-oxo-5-hydroxycyclohexanecarboxylate (III) in 11 steps. Attempt to enlarge the six-membered C-ring in (XX) to a seven-membered ring did not materialize.