90754-10-2Relevant academic research and scientific papers
THE FORMATION OF 3,4,6-TRI-O-BENZYL-2,5-ANHYDRO-L-IDITOL FROM 2,3,4,6-TETRA-O-BENZYL-D-GLUCOPYRANOSE. INTRAMOLECULAR DISPLACEMENT OF A SECONDARY MESYLOXY GROUP BY A BENZYLOXY GROUP, IN THE PRESENCE OF CESIUM PROPIONATE
Rao, Vanga S.,Perlin, Arthur S.
, p. 886 - 890 (2007/10/02)
The reaction between 2,3,4,6-tetra-O-benzyl-1,5-di-O-mesyl-D-glucitol and cesium propionate in dimethylformamide at 100 deg C leads to an almost quantitative conversion into 3,4,6-tri-O-benzyl-1-O-propionyl-2,5-anhydro-L-iditol.Closure of the anhydro ring appears to entail anchimeric assistance by the 2-O-benzyl substituent in an SN2 displacement at C-5, leading to an inversion at the latter position.Probable contributors to the marked regio- and stereoselectivity observed for the reaction are a unique property of cesium propionate as compared with other carboxylate salts, large differences in rate between competing reactions, and a geometry highly favorable to an intramolecular displacement process.Conformational properties of 2,5-anhydro-L-iditol, as well as of isomeric 2,5-anhydro-D-mannitol, are described, based on nmr evidence.
