Synthesis of polyoxygenated trans-decalins as potential insect antifeedants

2α, Acetoxy-1α-acetoxymethyl-5,5-dimethyl-1α,6β,10Oα-bicyclo[4.4.0]decane-10-spiro-2′-oxiran (4) has been prepared from 4,4-dimethylcyclohex-2-enone as a model compound in order both to probe the biological activity of, and to develop a synthetic strategy to, a number of clerodane-related insect antifeedants. The trans-decalin (4) was shown to inhibit feeding of Locusta migratoria at a comparable level to that of the natural product clerodin hemiacetal. Three other related decalin analogues were also synthesised and shown to have negligible antifeedant properties.