cis-Tetrahydrofuran-3,4-diol Structure as a Key Skeleton of New Protecting Groups Removable by Self-Cyclization under Oxidative Conditions

Abstract

A variety of carbonate-type acyl groups having a cis-tetrahydrofuran-3,4-diol (1,4-anhydroerythritol) backbone structure and a TrS or MMTrS group have been examined as new "protected" protecting groups of the 5'-hydroxyl group of nucleosides. These acyl groups were designed in a manner where they could be deprotected by I(2)-promoted removal of the TrS or MMTrS group followed by self-cyclization involving an intramolecular attack of the once-generated neighboring hydroxyl group on the acyl carbon. It turned out that these acyl groups could be introduced into the 5'-hydroxyl group of a 3'-O-protected thymidine derivative by use of the corresponding acyl imidazolides or 4-nitrophenyl esters as well as by reaction with carbonyldiimidazole or 4-nitrophenyl chloroformate. Among the acyl groups tested, it was found that the CTFOC group could be easily introduced into the 5'-hydroxyl group of 3'-masked deoxyribonucleoside derivatives and rapidly removed under mild conditions using iodine.

Enhancement of intrinsic thermal conductivity of liquid crystalline epoxy through the strategy of interlocked polymer networks

“…EAE was acquired commercially, while FPM was synthesized according to ref. 70 and 71. When FPM ( i.e.…”

Synthesis and biophysical properties of carbamate-locked nucleic acid (LNA) oligonucleotides with potential antisense applications

“…In order to synthesise compound 19 we activated the 5′-OH of unprotected thymidine but this led to an intramolecular reaction via 3′-OH nucleophilic attack on the PNP carbonate. Thus, a 5′/3′ protection strategy was employed similar to that of Utagawa et al ,38 where 5′- O -DMTr/3′- O -TBDMS protected thymidine was used in the generation of the 5′-activated PNP carbonate (compound 19 ) via compound 18 . Compound 22 was formed under basic conditions and 3′- O -TBDMS protection was removed to form alcohol 23 .…”

New potential prodrugs of aciclovir using calix[4]arene as a lipophilic carrier: synthesis and drug-release studies at the air–water interface

“…Indeed, dissymmetric carbonate derivatives can be formed by ''one-pot'' reaction involving two alcohols and 1,1 0 -carbonyldiimidazole (CDI), under moderate conditions and good yields. [36][37][38][39][40][41][42] In our case, this convergent strategy involved the preparation of a 2-N-protected aciclovir derivative, and of calixarene-O-(o-hydroxyalkyl) derivatives. The spacer was chosen identical to previous works, i.e.…”

“…In order to determine the precision of the method (repeatability and intermediate precision), each solution was fractioned in three portions of 100.0 mL, representatives of subphase sampling. All of nine solutions were treated according to the ST, and the corresponding standard-ST samples, that are S ST (10), S ST (40) and S ST (100), were analyzed by HPLC.…”