An Efficient Synthesis of 9-Methyl-5(10)-Octalin-1, 6-Dione

Abstract

9-Methyl-5(10)-octalin-1,6-dione (5)¹ has been extensively employed as a starting material for terpenoid and steroid synthesis.² Its preparation involves high pressure reduction of resorcinol (1) in alkaline solution followed by methylation to give 2-methylcyclohexane-1,3-dione.³ Annelation with methyl vinyl ketone completes the preparation.⁴ Following published procedures^3,4 a competent experimentalist can prepare dione 5 in 35–40% overall yield. In view of the widespread and continued use of this valuable synthetic intermediate we would like to report a modified synthetic scheme whereby dione 5 can be obtained by a two step sequence in greater than 60% overall yield.