THE ENE AND THE DIELS-ALDER REACTIONS OF CF3CHO WITH DIENES USING ZNX(2) (X-CL, OTF)

The reaction of CF3CHO with dienes using ZnX(2) (X: Cl, OTf) in organic solvents (CH2Cl2 or CH3NO2) gave fairly good results in depressing unfavorable reactions and affording the preferential formation of the ene react ion pro ducts, 1-trifluoromethyl-3-buten-1-ols, together with the Diels-Alder reaction pro ducts. Particularly, Zn(OTf)(2), which is insoluble in CH2Cl2, had some predominance for the formation of ene-type products in preference to ZnCl2, and could be recycled without any deterioration in its catalytic activity.