Abstract
Stable diastereomeric ethyl 1-benzoyl-6-(bromomethyl)-2,2,2,4-tetra- phenyl-3,7-dioxa-2λ 5 -phosphabicyclo[3.2.0]hept-4-ene-6-carboxylate was obtained in 98% yield from the reaction between dibenzoylacetylene as electron-deficient acetylenic compound, and ethyl 3-bromopyruvate in the presence of triphenylphosphine in dry ether.