A Pb/Al bimetal system was used to carry out reductive addition of tetrachloromethane, tetrabromomethane, bromotrichloromethane, trichloroacetamide, and trichloroacetonitrile to aldehydes. Subsequent 1,2-elimination of the halogen atom and hydroxyl group from the coupling products was also performed with the Pb/Al bimetal system. The technology was successfully applied to stereocontrolled syntheses of ethyl trans-and c¿s-3-(2,2dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates.

Reductive addition reaction of tetrachloromethane (IIa) to the aldehydes (I) in the presence of a Pb/Al bimetal system produces the trichloromethyl carbinols (III).

ChemInform Abstract The esters (VI) are obtained via reductive addition of CCl4 (II) to the aldehydes (I) followed by reductive 1,2-elimination of the hydroxy group and the chlorine atom.