Sulfurization of Dinucleoside Phosphite Triesters with Chiral Disulfides
作者:Joshua A. Mukhlall、William H. Hersh
DOI:10.1080/15257770.2011.597366
日期:2011.9
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 beta-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.