title: Facial selectivities in the nucleophilic additions of 2,3-unsaturated 3-arylsulfinyl pyranosides.
abstract: 2,3-Unsaturated 3-arylsulfinyl pyranosides undergo nucleophilic additions at C-2, with facial selectivities depending on the nucleophile and the substituent on sulfinyl sulfur. The reactions of such sugar vinyl sulfoxides lead to the addition of nucleophile preferring an axial orientation at C-2, with concomitant formation of an allylic bond at C-3 to C-4. This trend in the addition pattern is observed for primary amine, carbon and sulfur nucleophiles, whereas secondary amines prefer an equatorial addition at C-2. The effect of p-tolylthio- versus (p-isopropylphenyl)thio vinyl sulfoxide is that the equatorial nucleophilic addition is preferred even more with the latter vinyl sulfoxide.
authors: Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India.
authors: Arunima
authors: A
authors: Mukherjee
authors: Narayanaswamy
authors: N
authors: Jayaraman
mesh_terms: D006027:Glycosides / Q000737:chemistry*; D013379:Substrate Specificity; D013454:Sulfoxides / Q000737:chemistry
chemical_list: D006027:Glycosides; D013454:Sulfoxides
keywords: Conjugate additions; Nucleophiles; Stereoselective addition; Unsaturated sugars; Vinyl sulfoxides