The Reaction of 2-Ethoxy-1,3-oxathiolane with Carbonyl Compounds in the Presence of ZnCl2 or HgCl2

Abstract

In the reaction of 2-ethoxy-1,3-oxathiolane with carbonyl compounds in the presence of ZnCl2 or HgCl2, it has been found that only the breaking of the endocyclic bond (C–O or C–S bond) occurs, while the breaking of the exocyclic C–O bond to give the 1,3-oxathiolan-2-ium ion is unfavorable. This behavior is different from that of 2-ethoxy-1,3-dithiolane, in which the breaking of the endocyclic C–S bond occurs by means of HgCl2 and the exocyclic C–O bond, by means of ZnCl2.

2,4,4,6-Tetrabromo-2,5-cyclohexadienone (TABCO), N-Bromosuccinimide (NBS) and Bromine as Efficient Catalysts for Dithioacetalization and Oxathioacetalization of Carbonyl Compounds and Transdithioacetalization Reactions

“…The reaction mixture was stirred for the appropriate time. 48,49 General Procedure for Transdithioacetalization of Acetals, Diacetals, Ketals, Acylals, Enamines, Imines, After completion of the reaction, an aqueous solution of NaOH (5%, 25 mL) was added and the mixture was extracted with CHCl 3 (3 × 25 mL).…”