Synthesis and Conformational Analysis of Tetrahydroisoquinoline‐Fused 1,3,2‐Oxazaphospholidines and 1,2,3‐Oxathiazol­idines

Abstract

The cyclizations of tetrahydroisoquinoline 1,2-amino alcohols with phenylphosphonic dichloride, bis(2-chloroethyl)phosphoramidic dichloride, thionyl chloride and sulfuryl chloride were utilized to synthesize 1,5,6,10b-tetrahydro-1,3,2-oxazaphospholo[4,3-a]isoquinolines (2, 3), 1,5,10,10a-tetrahydro-1,3,2-oxazaphospholo[3,4-b]isoquinolines (8, 9), 1,5,6,10b-tetrahydro-1,2,3-oxathiazolo[4,3-a]isoquinolines (4-6) and a 1,5,10,10a-tetrahydro-1,2,3-oxathiazolo[3,4-b]isoquinoline (11), which are the first representatives of these ring systems. NMR spectroscopic analysis revealed the existence of conformational equilibria that are fast on the NMR timescale. Theo-

Synthesis of Acyclic and Cyclic Sulfamates: A Review

“…One of the most useful methods for the synthesis of five-and six-membered cyclic sulfamates is from β-amino alcohols and γ-amino alcohols. [71][72][73][74][75][76][77] Treatment of amino alcohols with thionyl chloride and subsequently oxidation of the prepared sulfamidite with sodium periodate in the presence of ruthenium trichloride as a catalyst in aqueous acetonitrile [78][79][80] or aqueous ethyl acetate, 81,82 resulted in the formation of the corresponding cyclic sulfamates 50 in high yield (Table 3). 81 It should be noted that the cyclic sulfamates can be used for the synthesis of amines.…”