A concise synthesis of (S)-3-hydroxytetrahydropyran from natural l-glutamic acid has been developed. The intramolecular etherification starting from 1,5-diol was promoted by trifluoromethanesulfonic anhydride. The clinnamates of the alcohols were prepared for accurately determining the optical purity by HPLC method.
A study into the synthesis and synthetic utility of (S)-3-benzyloxy-3,4,5,6-tetrahydropyridine N-oxide is described. This nitrone is readily accessed from L-glutamic acid and the regio- and stereoselectivity of cycloaddition of this compound with a range of alkenes has been probed. Reductive cleavage of the major cycloadducts provides access to a diverse range of trans-2,3-disubstituted piperidines. The synthetic scope of this nitrone is further illustrated by the use of this compound as a key intermediate in a concise synthesis of the anti-malarial agent (+)-febrifugine. (C) 2009 Elsevier Ltd. All rights reserved.