A General and Efficient Approach to Spirocyclohexadienones

Abstract

The widespread occurrence of functionalized spiro ring systems in numerous classes of natural products has made them the synthetic targets of many investigators. Despite these recent advances in spiro ring syntheses, there exists no general approach to spirocyclohexenones 1 and spirocyclohexadienones 2. The compelling need for simple and efficient methodology in this area of synthesis was reinforced in connection with a current synthesis of [6]- and [7]paracyclophanes. The project demanded large quantities of spiro[5.6]dodeca-1,4-dien-3-one 3 and spiro[5.7]trideca-l,4-dien-3-one 4.