Formation of Furan Derivatives from Phenacyl Bromides and Sodium Telluride; Attempted Extension to Coumarin Synthesis

Article abstract of DOI:10.1246/bcsj.62.2114

The enolates, generated from phenacyl bromides by sodium telluride, yield 2,4-diarylfurans in addition to the expected dehalogenation products.No 1,4-dicarbonyl compounds could be isolated even in the presence of excess oxidizing agent, copper(II) chloride.Condensation of 2-(methoxymethoxy)arenecarbaldehydes with ethyl bromoacetate in the presence of sodium telluride gave the expected α,β-unsaturated esters which resisted cyclization to yield the desired coumarin derivatives.Attempted intramolecular Reformatsky-type reaction of 2-(bromoacetoxy)benzaldehyde gave only 6,12-epoxy-6H,12H-dibenzo-<1,5>dioxocin as the major product.