Abstract The first example of the synthesis of 4, 5-disubstiuted furan-2 (5H)-ones by base- mediated tandem acyl shift/cyclization/decarbonylation reactions of aroylmethyl 2- alkynoates has been developed. This new and inexpensive tandem route allows both a C [BOND] O bond and a Csp 3 [BOND] Csp 2 bond forming in one step involving an unprecedented acyl rearrangement process.