Novel and Facile Syntheses of Alkenyl, Alkynyl, and Aryl 1,2-Diketones

Novel and facile routes to alkenyl, alkynyl, and aryl 1,2-diketones utilize treatment of benzotriazole derivatives 1, 7a,b, and 15a − d with butyllithium and subsequent reaction with esters or acid chlorides to yield the substituted intermediates 2a − d, 8a,b, and 16a − g. Reactions of the deprotonated 1 and 7 with α,β-unsaturated aldehydes followed by oxidation also produces similar intermediates 5 and 11a,b. Subsequent hydrolyses of the intermediates of type 2, 5, 8, 11, and 16 afford diverse 1,2-diketones in good yields.