Regiochemistry of Diels-Alder reaction of hexafluorothioacetone and dienes

Abstract

AbstractOK The reaction of 2,2,4,4-tetrakis(trifluoromethyl)-dithiethane-1,3 (1) with various hydrocarbon dienes is not regioselective and results in the formation of two isomeric Diels-Alder cycloadducts with the ortho isomer predominating. The reaction of non-conjugated dienes involves ene-insertion of hexafluorothioacetone (HFTA), followed by Diels-Alder reaction of the product of the ene- reaction with a second mole of HFTA, while the reaction of 1,1,4,4-tetramethylbutadiene-1,3 and 2,5-dimethylhexadiene-1,5 results exclusively in HFTA insertion into the allylic C H bond.