Studies Directed Towards a Practical Synthesis of Brevicomin (III) Cyclization Routes to 6, 8-Dioxabicyclo[3.2.1]octane

Abstract

Bicyclic ketals have been noted as an important structural unit in sugars¹, an alkaloid², a terpene³ and in pheromones. It is with regard to this last group that we have been recently directing our attention. Frontalin (1)⁴ and the brevicomins (2 and 3)⁵ are sex aggregating pheromones of Dendroctonus frontalisand D. brevicomis, respectively. Because of their potential utility in controlling populations of pine bark beetles, considerable activity has been directed towards their syntheses. ^6–10 Particularly in syntheses of brevicomin, where the exo-isomer (2) is the biologically useful isomer for insect control, does the methodology become quite important.