Benzodithiol-3-one 1,1-Dioxide

Desymmetrization by means of this methodology was successfully applied to a synthesis of key intermediates for mosin aspicilin, a7a-quercitol, andallosamizoline  

Disposal the reagent can be safely discarded in a chemical waste container. 

Maezaki, N. Sakamoto, A. Tanaka, T. Iwata, C., Tetrahedron Asymmetry 199i, 9, 179. 

Naoyoshi Maezaki Tetsuaki Tanaka Osaka University, Osaka, Japan 

Solubility soluble in most organic solvents except nonpolar solvent such as alkanes. 

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Reagents i, 3 -0-Tbdms-thymidine ii, 5 -0-Tbdms-thymidine, 2-bromo-4,5-dicyanoimidazole iii, 3-H-1,2-benzodithiol-3-one 1,1 -dioxide 109 iv. TFA... 

Dioxide. The sulfur-transfer reagent 3//-l,2-benzodithiol-3-one 1,1-dioxide (2, eq 1) is widely used in the preparation of oligonucleoside phosphorothioates, which are especially valuable in the development of therapeutic oligonucleotides against various t)q)es of cancer and infectious diseases in humans. ... 

Sulfurization of tricoordinated phosphorus compounds by treatment with 3H-1,2-benzodithiol-3-one 1,1-dioxide results from the nucleophilic attack of, for example, a phosphite triester on the electrophilic thiosulfonate function of 2 to produce the phos-phonium sulfinate intermediate 3 (eq 2). Intramolecular condensation of the sulfinate anion with the carbonyl group of the activated thiol ester function releases the phosphorothioate triester (4) with concomitant formation of 5. Because of the... 

Sulfurization of //-Phosphonate and //-Phosphonothioate Diesters Using 3i/-l,2-benzodithiol-3-one 1,1-Dioxide. Considering the efficiency with which phosphite triesters are converted to the corresponding phosphorothioate triesters upon reaction with 2, investigations on the use of 3i/-l,2-benzodithiol-3-one 1,1-dioxide in the sulfurization of //-phosphonate and //-phosph-onothioate diesters were undertaken. Conversion of the dinucleoside //-phosphonothioate diester (8) to its dithioated diester (9) is accomplished quantitatively within 30 s when a 0.02 M solution of 2 or 1 in 2% aqueous pyridine is used as a sulfurization reagent. 

Stawinski, J, Thelin, M, and von Stedingk, E (1991) Studies on sulfur-ization of nucleoside H-phosphonate and H-phosphonothioate esters using 3H-l,2-benzodithiol-3-one 1,1-dioxide. Nucleosides Nucleotides 10, 517,518. 

Prior to 1990, this step was commonly performed with an elemental sulfur solution in a pyridine-carbondisulfide mixture. The utilization of [3H]-1,2-benzodithiol-3-one-1,1 -dioxide by Iyer et al. (15) for converting phosphorus (III) triester into pentavalent phosphorothioate has simplified the process of large-scale polyphosphorothioated oligonucleotide synthesis following phosphoramidite chemistry. This reagent, however, fails to convert H-phosphonate diester linkages into phosphorothioate diester, which is still achieved by treating with 5% elemental sulfur solution in pyridine-carbon disulfide off the instrument. 

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