Diastereoselective Synthesis and Configurational Assignment of Novel Functionalized Cyclic Sulfamidites Precursors of Cyclic Sulfamidates

New 3,4,5-trisubstituted sulfamidites were prepared through cyclization of beta-amino alcohol diesters with thionyl chloride. The oxidation of these N-alkylated sulfamidites into the corresponding sulfamidates was then performed. Interestingly, the NMR spectra of the prepared sulfamidites revealed that the ratios of the exo and endo diastereomers of these compounds were influenced by the substituents on the a-carbon. In addition, theoretical calculations at the DFT B3LYP/6-31G(d) level were carried and indicated that the exo-diastereomers were more stable than the endo forms. (C) 2016 Wiley Periodicals, Inc.