New Stereospecific Method of Synthesis of [Sp]- and [Rp]-Dinucleoside-(3',5') Methanephosphonates

Synthesis and Stereochemical Characterization of Diastereomeric Nucleoside-Phosphorothioselenoates by NMR Methods

“…KAJTÁ R-PEREDY, TÖ MÖ SKÖ ZI, AND GÁ CS-BAITZ N,N-diisopropyl]-phosphoramidite with p-chloro-benzyl mercaptane in the presence of diethylaniline hydrochloride in dichloromethane and subsequent oxidation with selenium powder 8 . Purification of the product and separation into diastereomers was achieved in one step by column chromatography on silica gel.…”

Synthesis and NMR Structural Analysis of 2′‐OMe‐Uridin‐3′‐yl (3′,5′)‐5′‐O‐(N‐Isobutyryl‐2′‐OMe‐Cytidine) Methylthiophosphonates

“…We had previously demonstrated the diagnostic value of ROESY spectra for conformational analysis of diastereomeric 5Ј-O-DMT-nucleoside 3Ј-O-(S-methyl methylphosphonothiolates) and the corresponding Semethyl methylselenophosphonates, [18] monomers for stereospecific synthesis of dinucleoside (3Ј,5Ј) methylphosphonates. [19,20] Preliminary studies revealed that the removal of the 5Ј-protected group could simplify interpretation of NMR spectra. Therefore, each isomer (Fast-2 and Slow-2 eluting from silica gel plates) was separately treated with 2% dichloroacetic acid, affording partially protected dinucleotide 1, which was purified by flash column chromatography and subjected to NMR analysis.…”

Consequences of P‐Chirality in Chimeric 2′‐O‐Methyloligoribonucleotides with Stereoregular Methylphosphonothioate Linkages

“…[25] We demonstrated that Oligo-MePS, [26] considered as isosteric analogues of Oligo-MePO, [27] exhibit stereodependent binding properties towards complementary DNA or RNA targets. During our studies on the stereocontrolled synthesis of OligoMePO [28,29] we also evaluated stereospecific methods for PS Ǟ PO oxidation reactions [30] allowing conversion of OligoMePS to Oligo-MePO.…”