Hydroxy-functionalized conjugated nitroolefins as immediate precursors of spiroketals. A new synthesis of 1,7-dioxaspiro[5.5]undecane and (E)-2-methyl-1,7-dioxaspiro[5.6]dodecane

Abstract

The syntheses of 1,7-dioxaspiro[5.5]undecane 6a, the major component of sex pheromones of the fruit fly (Dacus oleae), and (E)-2-methyl-1,7-dioxaspiro[5.6]dodecane 6b, a component of the pheromone of Andrena haemorrhoa, have been achieved in two steps in 64 and 66% yields respectively.