title: Sulfurization of dinucleoside phosphite triesters with chiral disulfides.
abstract: Sixteen chiral analogues of phenylacetyl disulfide (PADS) and 5-methyl-3H-1,2,4-dithiazol-3-one (MEDITH) were used to sulfurize five dithymidine phosphite triesters, each incorporating a β-cyanoethoxy or siloxy group. Each mixture of S(P):R(P) phosphite triester diastereomers was combined with approximately one fourth of an equivalent of each of the sulfurizing reagents, and the R(PS):S(PS) diastereomer ratios of the resulting phosphite sulfides or phosphorothioates were determined by reverse-phase HPLC. Diastereoselectivities and corresponding diastereomeric excess (de) values were calculated by correcting for the starting triester diastereomer ratios. The highest de values for R(PS) and S(PS) phosphorothioates were 14.7% and 7.9%, respectively, both using MEDITH analogues.
authors: Department of Chemistry and Biochemistry, Queens College and the Graduate Center of the City University of New York, Flushing, New York, USA.
authors: Joshua A
authors: JA
authors: Mukhlall
authors: William H
authors: WH
authors: Hersh
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D017905:Phosphites / Q000737:chemistry*; D013237:Stereoisomerism; D013873:Thionucleotides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004220:Disulfides; D009841:Oligonucleotides; D017905:Phosphites; D013873:Thionucleotides