TRISUBSTITUTED BENZOATE SYNTHESIS VIA CAR BOPALLADATION OF ALLENES

The carbopalladation of allenes in the presence of the enolate of ethy l acetoacetate leads to good yields of 1,3-dienes of general formula 1 . When treated with trimethylsilyl triflate, these dienes 1 are genera lly transformed into benzoic esters substituted in the ortho, para and meta positions. The ease of the cyclization, which involves the attac k of the carbonyl group, on the delta-double bond, is greatly influenc ed by the substitution of the dienic moiety.