Synthesis of 3-Acyl-1,2-benzisoxazoles

A convenient method for the synthesis of 3-acyl-1,2-benzisoxazoles, which are unstable toward bases, is described. Base-catalyzed cyclization of 2-alkyl- and aryl-1,3-dithian-2-yl o-chlorophenylketoximes 4a-1 gave 3-(2-alkyl- and aryl-1,3-dithian-2-yl)-1,2-benzisoxazoles 8a-1 , which were converted into the corresponding 3-acyl-1,2-benzisoxazoles 1a-1.