Stereospecific Synthesis of the Saccharosamine-Rhamnose-Fucose Fragment Present in Saccharomicin B

Organic Letters

2018, 20 (15), pp 4695–4698

DOI: 10.1021/acs.orglett.8b02028

Abstract

A synthetic route has been developed for constructing the d-saccharosamine-l-rhamnose-d-fucose (Sac-Rha-Fuc) trisaccharide fragment present in the antibacterial natural product saccharomicin B. The Sac monosaccharide was synthesized through a modified nine step procedure starting from d-rhamnal in 23% overall yield. 1-O-TBS Sac donors were used to construct the β-linked Sac-Rha disaccharide. This disaccharide was coupled to a Fuc acceptor under BSP/Tf₂O conditions to afford a trisaccharide properly functionalized for elaboration to saccharomicin B.