Geetanjali Agnihotri

Nitric acid mediated oxidative transformation of thiols to disulfides

Abstract Oxidation of thiols to disulfides are reported using nitric acid/methylene chloride. Environmentally benign, economically convenient and simple reaction condition represents an attractive alternative to the existing approaches on both the laboratory and the industrial scale. #C.D.R.I. Communication No: 6412.

Modified One‐Pot Protocol for the Preparation of Thioglycosides from Unprotected Aldoses via S‐Glycosyl Isothiouronium Salts*

An efficient one‐pot protocol for the direct preparation of thioglycosides starting from unprotected reducing sugars via S‐glycosyl isothiouronium salts is reported. In this one‐pot methodology, BF3 · OEt2 has been used as a general catalyst for both per‐O‐acetylation of sugars and conversion of sugar per‐O‐acetates into S‐glycosyl isothiouronium salts, which was allowed to react with alkylating agents in the presence of a base to furnish thioglycosides in excellent yield. *C.D.R.I. communication no. 6767. Authors contributed equally to this work.

Practical synthesis of sulfated analogs of lactosamine and sialylated lactosamine derivatives

Abstract A series of β‐D‐Gal‐(1 → 4)‐β‐D‐GlcNAc‐octyl, NeuAcα‐(2 → 3)‐β‐D‐Gal‐(1 → 4)‐β‐D‐GlcNAc‐octyl, and their 6‐O‐sulfated and 6′‐O‐sulfated analogs (1–6) were synthesized in a concise manner starting from readily accessible monosaccharide intermediates. The syntheses involved formation of an orthogonally protected disaccharide and a trisaccharide from which all six compounds were derived. #C.D.R.I. Communication no. 6456.

Unprecedented Transformation of Thioglycosides to Their Corresponding 1‐O‐Acetates in the Presence of HClO4‐SiO2 §

An unprecedented conversion of thioalkyl/aryl glycoside to the corresponding 1‐O‐acetates has been described using acetic anhydride and HClO4‐SiO2 at rt. Although this transformation does not play an important role in the oligosaccharide synthesis in comparison to its reverse transformation, this gives useful information in selecting the reaction condition for the synthesis of oligosaccharides. The yields were excellent in all cases. §C.D.R.I. communication no. 6979.