200931-85-7

Upstream product

• 440114-91-0 (1aR,1bS,4aS,5aR)-1a-(tert-Butyl-dimethyl-silanyloxy)-3-methoxy-hexahydro-2-oxa-cyclopropa[a]pentalen-4a-ol 
• 148905-15-1 (1R,5R,6S)-6-(2'-hydroxyethyl)-3,3-dimethyl-2,4-dioxabicyclo[3.3.0]octan-6-ol 
• 200931-83-5 N-{9-[(1aR,1bS,3S,4aS,5aS)-1a-(tert-Butyl-dimethyl-silanyloxy)-4a-trimethylsilanyloxy-octahydro-2-oxa-cyclopropa[a]pentalen-3-yl]-9H-purin-6-yl}-benzamide 

Downstream Products

• 918886-47-2 (3'S,5'R,6'R)-N⁶-benzoyl-9-{2'-deoxy-5'-O-(4,4'-dimethoxytrityl)-3',5'-ethano-5',6'-methano-α-D-ribofuranosyl}adenine 

Relevant academic research and scientific papers

Synthesis and pairing properties of α-tricyclo-DNA

We describe the synthesis of the phosphoramidite building blocks of α-tricyclo-DNA (α-tc-DNA) covering all four natural bases, starting from the already known corresponding α-tc-nucleosides. These building blocks were used for the preparation of three α-t

Nucleic-Acid Analogs with Constraint Conformational Flexibility in the Sugar-Phosphate Backbone 'Tricyclo-DNA' - Part 1: Preparation of [(5′ R,6′ R)-2′-Deoxy-3′,5′-ethano-5′,6′-methano-β-D- ribofuranosyl]thymine and -adenine, and the Corresponding Phosphoramidites for Oligonucleotide Synthesis

The synthesis of the tricyclo-deoxynucleoside analogs 1 and 2 and of the corresponding cyanoethyl phosphoramidite building blocks 16 and 21 for oligonucleotide synthesis is described. These tricyclic deoxynucleoside analogs differ from the recently introduced bicyclo-deoxynucleosides by an additional cyclopropane unit joined to the centers C(5′) and C(6′) of the latter (see Fig. 1), and thus represent a further member of the class of nucleoside analogs with constraint conformational flexibility. The synthesis of the tricyclo-deoxynucleosides was achieved by a diastereoselective carbene addition to the enantiomerically pure silyl enol either 8/9 and a Vorbru?ggen condensation of the tricyclic carbohydrate unit 10/11 with in situ persilylated thymine and N6-benzoyladenine. Selective tritylation of the tertiary OH-C(5′) and phosphinylation of OH-C(3′) of 1 and 2 afforded the corresponding phosphoramidites 16 and 21. The 'exo'-configuration of the newly introduced cyclopropane ring was confirmed by 1H-NMR-NOE spectroscopy. The α-D- and β-D-configuration at C(1′) of the nucleoside analogs 1 and 14 (2 and 19, resp.) was assigned by 1H-NMR-NOE spectroscopy and NOESY. Modeling studies of the β-D-anomeric nucleoside analog 1 indicate a preference for the 2′-endo-conformation of the furanose ring and a partial correction of the torsion angle γ to the anti-clinal range compared to bicyclo-deoxynucleosides.