2‐Ketophenyl Assisted Biomimetic Synthesis of 3‐Thio Substituted Glycals at Room Temperature

Abstract

Herein we designed a strategy for the synthesis of regioselective and stereoselective displacement of C‐3 acetate group in the presence of other C‐4 and C‐6 acetate of 2‐ketophenyl‐glycal by different aromatic and cyclic aliphatic thiol nucleophiles taking inspiration from cytosolic esterase mediated thiolation of glucosamine sugars into cellular glycan. Under a mild base condition at room temperature, the protocol generated a library of 3‐arylthiosugars with excellent yields and high axial selectivity. This stereoselective approach tolerated well with different ester‐protected glycals and thiophenols, aliphatic cyclic thiols, and mercaptans. A variety of control experiments were conducted to establish the mechanism and reason behind the stereoselectivity.