Thiocrown ethers containing thioacetal units are readily prepared by r
eaction of the cesium salts of long chain dithiols with methylene dibr
omide. Preparation of the trimethylsilyl derivatives followed by conde
nsation with aldehydes under basic conditions (Peterson reaction) lead
s to the expected macrocycles with exocyclic double bonds at the thioa
cetal carbon atom. (C) 1998 Elsevier Science Ltd. All rights reserved.