title: Locked nucleosides based on oxabicyclo[3.2.1]octane and oxabicyclo[2.2.1]heptane skeletons.
abstract: Intramolecular nitrone cycloaddition (INC) reaction on a d-glucose derived substrate carrying an allyl group at C-1 and an enose-nitrone at C-5 or an aldehyde-nitrone at C-1 and vinyl group at C-4 furnished a tricyclo[6.2.1.0(2,6)]undecane or a tricyclo[5.2.1.0(2,6)]decane ring structure. These tricycles were converted to bicylic nucleosides with oxabicyclo[3.2.1]octane and oxabicyclo[2.2.1]heptane rings in three steps. An oxabicyclo[3.2.1]octane ring compound could alternatively be formed by RCM reaction between C-1-allyl and C-4-vinyl moieties and transformed to nucleoside analogues through a nucleophilic substitution reaction. Participation of a neighboring benzyl ether substituent in one case paved the way for an enantiodivergent synthesis.
authors.affiliation: Department of Chemistry, Indian Institute of Chemical Biology (a unit of CSIR), 4, Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032, India.
authors.forename: Ramprasad
authors.initials: R
authors.lastname: Ghosh
authors.forename: Joy Krishna
authors.initials: JK
authors.lastname: Maity
authors.forename: Basudeb
authors.initials: B
authors.lastname: Achari
authors.forename: Sukhendu B
authors.initials: SB
authors.lastname: Mandal
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis*; D003500:Cyclization; D005947:Glucose / Q000737:chemistry; D006536:Heptanes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009705:Nucleosides / Q000737:chemistry*; D009795:Octanes / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D001643:Bridged Bicyclo Compounds; D006536:Heptanes; D009705:Nucleosides; D009795:Octanes; D005947:Glucose; C026728:octane