3‘-C-Branched LNA-Type Nucleosides Locked in an N-Type Furanose Ring Conformation: Synthesis, Incorporation into Oligodeoxynucleotides, and Hybridization Studies
protected 3‘-C-branched LNA-type phosphoramidite building blocks 17, 27, and 38, containing furanose rings locked in an N-type conformation, were synthesized from a known 3-C-allyl allofuranose derivative using strategies relying on the introduction of the branching alkyl chain before condensation with the nucleobase. Synthesis of 3‘-C-hydroxypropyl derivatives proved superior to synthesis of the 3‘-C-hydroxyethyl