Synthesis 2005(6): 893-898  
DOI: 10.1055/s-2005-861833
PAPER
© Georg Thieme Verlag Stuttgart · New York

Enantiospecific Synthesis of Both Enantiomers of 2-Benzyloxydihydropyran-3-ones from Arabinose

María Laura Uhrig, Oscar Varela*
CIHIDECAR-CONICET, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, 1428, Buenos Aires, Argentina
Fax: 54(11)45763346; e-Mail: varela@qo.fcen.uba.ar;
Further Information

Publication History

Received 25 June 2004
Publication Date:
21 February 2005 (online)

Abstract

Approaches to the enantioselective synthesis of the useful building blocks (2R)- and (2S)-2-benzyloxy-2(H)-pyran-3(6H)-one (12 and 17, respectively) are described. The most direct and highly yielding route for the synthesis of 12 was based on the ‘one-pot’ preparation of benzyl 2-O-acetyl-arabinopyranoside 3,4-thio­nocarbonates (7 and 14) from benzyl β-l- or β-d-arabinopyranosides (1 and 13). Trimethylphosphite-promoted olefination, followed by O-deacetylation and oxidation gave the optically pure enantiomeric enones 12 and 17 in about 50% overall yield.