title: Chemoenzymatic synthesis of C-4'-spiro-oxetanoribonucleosides.
abstract: Novozyme-435-mediated diastereoselective deacylation of one of the two diastereotopic acyloxymethyl groups in 5-O-acyl-4-C-acyloxymethyl-3-O-benzyl-1,2-O-isopropylidene-α-D-ribofuranose has been achieved in quantitative yield. The exclusive selectivity of the lipase for the 5-O-acyl over the 4-C-acyloxymethyl group in the substrate was confirmed by chemical transformation of enzymatically monodeacetylated compound to 1,2-O-isopropylidene-C-4-spiro-oxetanoribofuranose. Further, the selective biocatalytic deacylation methodology has been utilized for the efficient synthesis of C-4'-spiro-oxetanoribonucleosides of uracil (U) and thymine (T) in 37 and 45% overall yields, respectively.
authors.affiliation: Bioorganic Laboratory, Department of Chemistry, University of Delhi , Delhi 110 007, India.
authors.forename: Vivek K
authors.initials: VK
authors.lastname: Sharma
authors.forename: Manish
authors.initials: M
authors.lastname: Kumar
authors.forename: Deepti
authors.initials: D
authors.lastname: Sharma
authors.forename: Carl E
authors.initials: CE
authors.lastname: Olsen
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Prasad
mesh_terms: D015394:Molecular Structure; D009005:Monosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D012263:Ribonucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013941:Thymine / Q000737:chemistry*; D014498:Uracil / Q000737:chemistry*
chemical_list: C000595358:5-O-acyl-4-C-acyloxymethyl-3-O-benzyl-1,2-O-isopropylidene-alpha-D-ribofuranose; D009005:Monosaccharides; D012263:Ribonucleosides; D013141:Spiro Compounds; D014498:Uracil; D013941:Thymine