Unexpected Nucleophile Masking in Acyl Transfer to Sterically Crowded and Conformationally Restricted Galactosides.

ABSTRACT: Design and synthesis of orthogonally protected monosaccharide building blocks are crucial for the preparation of well-defined oligosaccharides in a stereo- and regiocontrolled manner. Selective introduction of protecting groups to partially protected monosaccharides is nontrivial due to the often unpredictable electronic, steric, and conformational effects of the substituents. Abolished reactivity toward a commonly used Lewis base-catalyzed acylation of O-2 was observed in conformationally restricted 4,6-O-benzylidene-3-O-Nap galactoside. Investigation of analogous systems, crystallographic characterization, and quantum chemical calculations highlighted the overlooked conformational and steric considerations, the combination of which produces a unique passivity of the

SUBMITTER: Sukhran Y 

PROVIDER: S-EPMC10337027 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature