Regioselective dihydropyran formation from 4-iodo-2,6-disubstituted tetrahydropyran derivatives using In(OAc)(3)/LiI system as the promoter
Résumé
The rapid and regioselective synthesis of a series of 2,6-disubstituted dihydropyranic building-blocks bearing an oxygenated side chain is described. The corresponding 4-iodo tetrahydropyran precursors, easily prepared by Prins cyclization, underwent regioselective elimination in the presence of an In(OAc)(3)/LiI system to provide the title compounds. The one-pot Prins cyclization-elimination process was also studied and could be achieved with the TMSBr/Lil/In(OAc)(3) system. (C) 2015 Elsevier Ltd. All rights reserved.