H. van den Elst

An efficient approach toward the synthesis of phosphorothioate diesters via the schönberg reaction

Abstract Easily accessible phenacetyl or benzoyl disulfide proved to be very convenient reagents for a rapid P-sulfurization of phosphite-triesters and H-phosphonate diesters, respectively.

An efficient approach to the synthesis of thymidine derivatives containing phosphate-isosteric methylene acetal linkages

Abstract Iodonium ion promoted condensation of properly protected 3′- O -methylthiomethyl or 3′- O -(4-penten-1-oxymethyl)-thymidine with 3′- O -methoxyacetyl-thymidine, was explored. A judicious choice of the iodoinium source and protecting groups led to an efficient preparation of thymidine dimers having internucleosidic-3′5′)-methylene bonds. The latter procedure was utilized towards the synthesis, in solution and on a solid support, of DNA-fragments containing one or more T- CH 2 -T dimers. Further, 5′- O -methylthiomethyl-3′- O -methoxyacetyl-N 3 -benzoyl-thymidine proved to be a suitable donor for the introduction of 5′- O -methylene acetal-linkages between 2,3,4,6-tetra- O -benzyl-D-glucose, benzyl N -benzyloxycarbonyl-L-serine and dibenzyl phosphate.

Synthesis of alkylphosphon(othio)ate analogues of DNA

Easily accessible bis(diisopropylamino)alkylphosphines (alkyl is methyl, n-butyl or n-octyl) are convenient reagents for the synthesis of DNA fragments having an alkylphosphonate or alkylphosphonothioate linkage at a predetermined site in solution and on solid support.