Process for the preparation of 2,2,4,4-tetrasubstituted 1,3,5-cyclohexanetriones of the formula I, ##STR1## by reaction of a cyclobutane-1,3-dione of the formula II ##STR2## with an O or N nucleophile and a silylating reagent, and subsequent acetylation and cyclization.

Processo para a preparação de 2,2,4,4-tetrasubstituted 1,3,5-cyclohexanetriones da fórmula I, ## do ## STR1 pela reação de um cyclobutane-1,3-dione do ## do ## STR2 da fórmula II com um O ou um N nucleophile e um reagent silylating, e acetylation e cyclization subseqüentes.