Unusual Azetidine or Oxazine Formation upon Reaction of O-Ethyl Dithiocarbonate with 1,2,3-Triphenyl-3-Phthalimidopropyl Iodides; Erythro Selectivity in the Reaction of Iodotrimethylsilane with Phthalimidopropanols

Abstract

Reaction of isomeric 1,2,3-triphenyl-3-phthalimidopropanols with hexamethyldisilane and iodine gave highly selectively iodides 3 with 1,2-erythro configuration which treated with O-ethyl dithiocarbonate yielded from ET-3 the xanthate ester 4, the trans,trans-dihydrooxazine 5 and the olefin 6 as major products while from EE-3 the cis,trans-azetidine 7 was obtained in 75% yield.