64. Synthesis of (5R)- and (5S)-5-Methyl-5,6-dihydrouridine Derivatives

Article abstract of DOI:10.1002/hlca.19830660232

The hydrogenation of 2',3'-O-isopropylidene-5-methyluridine (1) in water over 5percent Rh/Al2O3 gave (5R)- and (5S)-5-methyl-5,6-dihydrouridine (2), separated as 5'-O-(p-tolylsulfonyl)- (3) and 5'-O-benzoyl- (5) derivatives by preparative TLC. on silica gel and ether/hexane developments.The diastereoisomeric differentiation at the C(5) chiral centre depends upon the reaction media and the nature of the protecting group attached to the ribosyl moiety.The synthesis of iodo derivatives (5R)- and (5S)-4 is also described.The diastereoisomers 4 were converted into (5R)- and (5S)-2',3'-O-isopropylidene-5-methyl-2,5'-anhydro-5,6-dihydrouridine (7).