Synthesis of Acylacetylenes from ?-Diazo-?-Hydroxylcarbonyl Compounds

Abstract

A facile synthesis of α-diazo-β-hydroxy ketones and esters by the condensation of aldehydes or ketones with acyldiazomethanes was reported recently.² Exposure of the trifunctional compounds to boron trifluoride in ether-acetonitrile solution leads to acylacetylenes. Thus substances 1 and 3 were converted readily into acetylenes 2 and 4 respectively.³ This makes available a simple two-step procedure for the synthesis of conjugated acetylenic carbonyl compounds.