Diastereoselective and regioselective synthesis of conformationally restricted thio-dioxa- and oxo-oxathiaphosphorinane dinucleotides featuring noncanonical alpha/beta torsion angle combinations (alpha,beta-CNAs)

摘要

Control of the regioselective cyclisation of a stereodefined 5'-C-tosyloxy phosphorothioate dinucleotide unit to provide conformationally restricted dinucleotides of either thio-dioxa- or oxo-oxathiaphosphorinane types is described. NMR structural analysis of the newly synthesized building units showed the alpha and beta torsional angles to be constrained to non-canonical values (gauche(+), trans) or {anticlinal(-), trans}. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).