Studies towards the synthesis of hyperireflexolide A

The first approach to hyperireflexolide A, based on the synthesis of γ-lactone-fused cyclopentane 5, a functionalized key intermediate, is presented. Compound 5 is involved in hydrolysis, α-allylation at C-8 and α-methylation at C-10 stereoselectively from the convex face. Then it is subjected to cross metathesis to give α,β-unsaturated ketone 11 as precursor in the total synthesis of hyperireflexolide A.