Thymidine selective deacylation

Tetrahydrofuranyl ethers of thymidine and 2 -deoxycytidine have been prepared by acid-catalysed reaction of the nucleosides with 2,3 dihydrofuran mixtures of the 3 - and 5 -mono- and 3 5 -di-ethers were obtained. 3 -0-Tetra-hydrofuranyl-thymidine was also obtained by etherification of 5 -6>-palmitoyl thymidine followed by deacylation, and rat liver microsomes were found to convert the 3, 5 -diether selectively to the 5 -ether. The puramycin analogues (58) has been prepared from a 5 -blocked adenosine derivative. 

Interest continues in the use of enzymes fcH- selective acylation and deacylation of nucleosides (see last three Vrdumes). Using oxime esters as acyl drmors, the lipase from Candida antarctica forms esters at 0-5 of libonucleosides and deoxyribonucleosides with good regioselectivity, and the same selectivity was found with the same enzyme in the butanoylation of a-thymidine, xy/o-thymidine, arabinofuranosyl nucleosides, and 2,2 -anhydiouridine.2 3 Chemo-en matic routes to 2 -deoxynucleoside urethanes are indicated in Scheme 14.724 when... 

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See also in sourсe #XX -- [ , , ]

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