Enantiospecific synthesis of both enantiomers of 2-benzyloxydihydropyran-3-ones form arabinose

MARÍA LAURA UHRIG; OSCAR VARELA

SYNTHESIS-STUTTGART

Georg Thieme Verlag Stuttgart

Año: 2005 vol. 2005 p. 893 - 898

0039-7881

Approaches to the enantioselective synthesis of the useful building blocks (2R) and (2S)-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-acetylarabinopyranoside 3,4-thionocarbonates (7 and 14) from benzyl beta-L or beta-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.