title: Synthesis of bicyclic 2'-deoxynucleosides with alpha-L-ribo- and beta-D-xylo-configurations and restricted S- and N-type conformations.
abstract: Two bicyclic 2'-deoxynucleoside analogues are synthesized in 12 steps each from thymidine. With a six-membered ring fused to the C3'-C4' bond and an alpha-L-ribo- and a beta-D-xylo-configuration, these are conformationally restricted in an S- and an N-type conformation, respectively. The constitutions were proven by X-ray crystallography. The beta-D-xylo-configured analogue is successfully converted to a 3'-phosphoramidite and incorporated into oligodeoxynucleotides, which are found to hybridize to DNA and RNA complements with decreased affinity.
authors.affiliation: Nucleic Acid Center, Department of Physics and Chemistry, University of Southern Denmark, 5230 Odense M, Denmark.
authors.forename: Khalil I
authors.initials: KI
authors.lastname: Shaikh
authors.forename: Surender
authors.initials: S
authors.lastname: Kumar
authors.forename: Lene
authors.initials: L
authors.lastname: Lundhus
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bond
authors.forename: Pawan K
authors.initials: PK
authors.lastname: Sharma
authors.forename: Poul
authors.initials: P
authors.lastname: Nielsen
mesh_terms: D001483:Base Sequence; D032701:Biomimetics; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D002236:Carbohydrate Conformation; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009691:Nucleic Acid Denaturation; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012266:Ribose / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity; D044366:Transition Temperature; D014994:Xylose / Q000737:chemistry*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D009705:Nucleosides; D009841:Oligonucleotides; C051802:triplex DNA; D012313:RNA; D012266:Ribose; D004247:DNA; D014994:Xylose