Simplifying Access to 3, 4-Di-O-acetyl-1, 5 anhydro-2, 6-dideoxy-D- lyxo-hex-1-enitol (3, 4-Di-O-acetyl-d-fucal)

Abstract

196 N-Acetyl-d-fucosamine (d-FucNAc) is a rare sugar found in a variety of bacterial glycoconjugates. 1 Chemical synthesis of their repeating units heavily relies on the use of orthogonally protected d-FucNAc-derived building blocks, which are available from diverse precursors. 2 Azidonitration of the title 3, 4-di-O-acetyl-D-fucal2b, 3 (3, 4-di-O-acetyl-1, 5-anhydro-2, 6-dideoxy-d-lyxo-hex-1-enitol) has been routinely used in this laboratory to produce large quantities (>20.0 g) of d-fucosamine and derivatives thereof. Accessing the title compound 3 on a large scale from commercially available d-fucose is prohibitively expensive. We have developed a convenient, six-step procedure to produce this valuable compound in 34%-40% overall yield, starting from commercially available 1, 2:3, 4-di-O-isopropylidene-d-galactose.