THE 1,1-DIANISYL-2,2,2-TRICHLOROETHYL GROUP AS 2'-HYDROXYL PROTECTIONOF RIBONUCLEOTIDES

The 1,1-dianisyl-2,2,2-trichloroethyl group (DATE, 1) was introduced a s a new 2'-hydroxyl protecting group of ribonucleotides. The usefulnes s of DATE as a 2 OH protection was demonstrated in the solid phase syn thesis of a dinucleotide by the phosphoramidite method. Starting from 2'-O-DATE-uridine (5), a suitable protected building block 7 was thus prepared and condensed in a conventional DNA synthesizer with the unpr otected 5'-hydroxyl group of thymidine bound to a support via the 3'-h ydroxy group. The resulting chimeric dinucleotide was cleaved from the support and the protecting groups were removed to yield 8. Cleavage o f DATE was performed by means of lithium cobalt(I)phthalocyanine smoot hly and quantitatively without any byproduct formation.