A convenient procedure for the deoxygenation and homologation of D-ribose derivatives

Abstract

5-O-Acetyl- and 5-O-diphenyl-t-butylsilyl-2,3-di-O-acetyl-D-ribonolactones were converted into the corresponding 3-deoxy-2-O-acetyl-D-arabinolactone derivatives (9a) and (9b) by sequential reaction with 1,8-diazabicyclo[5.4.0]undec-7-ene and hydrogen over palladium on carbon. Reaction of (9a) and (9b) with sodium borohydride, 2,4,6-tri-isopropylbenzenesulphonyl chloride and potassium cyanide in sequence respectively gave the (3S,5S)-nitriles [XCH₂CH(OH)CH₂CH(OH)CH₂CN (10c; X = CN) and (10f; X = Ph₂Bu^tSiO)]. The latter was hydrolysed and silylated to produce (4S,6S)-4-dimethyl-t-butylsilyloxy-6-[(dimethyl-t-butylsilyloxy)methyl]tetrahydro-2H-pyran-2-one(5b).