Development of diastereoselective birch reduction-alkylation reactions of bi- and tricyclic β-alkoxy-α,β-unsaturated ketones

(Chemical Equation Presented) Diastereoselective Birch reduction-alkylation reactions of bicyclic β-alkoxy-α,β-unsaturated carbonyl compounds and tricyclic analogues were investigated. Although the relative configuration of the product was altered according to the structure of the starting material, stereoselectivity of the reaction could be accounted for by similar reaction pathways. The product from the tricyclic β-alkoxy-α, β-unsaturated carbonyl compound corresponded to the trichothecene skeleton.