Selective Cleavage of 2,2,2-Trichloroethyl Esters with Activated Zinc Dust in the Presence of Phthalimido Group

[摘要] Four 2, 2, 2-trichloroethyl esters possessing a phthalimido group, 2,2,2-trichloroethyl phthalimidoacetate (1a), 2,2,2-trichloroethyl 6-phthalimidohexanoate (2a), 2,2,2-trichloroethyl 2-phthalimidopropanoate (3a) and 2,2,2-trichloroethyl N-phthaloylcarbamate (4a) were prepared and treated with zinc dust in aqueous acetic acid(Method A), in aqueous THF(Method B), and in aqueous THF containing triethylamine (Method C). By Methods A and B, 2,2,2-trichloroethyl ester linkage of the compounds 1a, 2a and 3a was reductively cleaved with concurrent reduction of phthalimido group to a 3-hydroxyphthalimidino group. By employing Method C, however, 2,2,2-trichloroethyl ester linkage of all the four compounds was selectively cleaved while the phthalimido group was preserved.

[学科分类] 化学（综合）