Studies on the intramolecular Claisen condensation. Stereospecific ring-closure of β-acetyloxy esters
Abstract
On treatment with lithium bis(trimethylsilyl)amide, α-alkyl-β-acetyloxy esters (2) and (3) undergo stereospecific ring-closure to the 5,6-dihydro-4-hydroxy-2H-pyran-2-ones(2,4-dioxotetrahydropyrans)(4) and (5).