A CONCISE THIAZOLE MEDIATED SYNTHESIS OF L-(-)-RHODINOSE FROM (S)-ETHYL LACTATE. THE THIAZOLE ROUTE TO DEOXYSUGARS

Article abstract of DOI:10.1016/S0040-4020(01)81092-9

2-Lithiothiazole (2-LTT) (1a) and 2-thiazolylmethylenetriphenylphosphorane (2-TMP) (1b) are employed as aldehyde equivalents in a new concise synthesis of 4-O-tert-butyldimethylsilyl L-(-)-rhodinose (2b) from (S)-ethyl lactate.The key intermediates in the synthesis are two differentially protected hydroxyl aldehydes, i.e. the 4-deoxy-L-threose derivative 3b and the (S,S)-4,5-dihydroxyhexanal derivative 4b which are obtained in high yield starting from O-benzyloxymethyl (S)-ethyl lactate (5).The selective C₅ hydroxyl deprotection in 4b leads to the TBS-protected rhodinose 2b in the pyranose form.A complete (1)H and (13)C NMR analysis of 2b is provided.