title: Synthesis of oxepane ring containing monocyclic, conformationally restricted bicyclic and spirocyclic nucleosides from D-glucose: a cycloaddition approach.
abstract: Carbohydrate-derived substrates having (i) C-5 nitrone and C-3-O-allyl, (ii) C-4 vinyl and a C-3-O-tethered nitrone, and (iii) C-5 nitrone and C-4-allyloxymethyl generated tetracyclic isoxazolidinooxepane/-pyran ring systems upon intramolecular nitrone cycloaddition reactions. Deprotection of the 1,2-acetonides of these derivatives followed by introduction of uracil base via Vorbrüggen reaction condition and cleavage of the isooxazolidine rings as well as of benzyl groups by transfer hydrogenolysis yielded an oxepane ring containing bicyclic and spirocyclic nucleosides. The corresponding oxepane based nucleoside analogues were prepared by cleavage of isoxazolidine and furanose rings, coupling of the generated amino functionalities with 5-amino-4,6-dichloropyrimidine, cyclization to purine rings, and finally aminolysis.
authors: Department of Chemistry, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
authors: Subhankar
authors: S
authors: Tripathi
authors: Biswajit G
authors: BG
authors: Roy
authors: Michael G B
authors: MG
authors: Drew
authors: Basudeb
authors: B
authors: Achari
authors: Sukhendu B
authors: SB
authors: Mandal
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D005947:Glucose / Q000737:chemistry*; D008968:Molecular Conformation; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D009705:Nucleosides; D013141:Spiro Compounds; D005947:Glucose