posted on 2005-07-22, 00:00authored byDiana S. Stoianova, Alan Whitehead, Paul R. Hanson
A strategy relying on the utilization of stereoselective additions to allyldiphenylphosphonate esters
and subsequent ring-closing metathesis (RCM) to access P-chiral P-heterocyclic building blocks
for the synthesis of phosphono sugars is described. These building blocks possess several attractive
components, including the following: (i) P(2) and C(6) stereogenic centers for directing stereoselective
transformations; (ii) an activated C(3) methylene group that promotes base-mediated olefin
transposition to generate vinyl phosphonates available for further stereoselective reactions; and
(iii) a P(2)-stereogenic center containing an exchangeable phosphonate ester armed to attenuate
the “stereochemical environment” at phosphorus. Taken collectively, these attributes contribute to
a concise method for the stereoselective synthesis of an array of P-sugars.