DIASTEREOSELECTION IN A DIRECTED CROSSED ALDOL REACTION BETWEEN TWO POLYOXYGENATED KETONES EMPLOYING TIN(II) ENOLATES. A FACILE STEREOSELECTIVE SYNTHESIS OF ETHYL 2-C-METHYL-DL-LYXOFURANOSIDE
Tin(II) enolates of 1,3-dihydroxy-2-propanone derivatives react with a second ketone, methyl pyruvate, under mild conditions to afford the corresponding anti-crossed aldol products in moderate to excellent yields. Facile elaboration to the branched-chain sugar, ethyl 2-C-methyl-DL-lyxofuranoside, was demonstrated.