Rapid syntheses of protected 2'-deoxycytidine derivatives

Nucleic Acid Related Compounds. 127. Selective N-Deacylation of N,O-Peracylated Nucleosides in Superheated Methanol1

“…Acyl groups have been removed by both chemical and enzymatic procedures. Selective N-acylation of nucleobases has been employed for temporary protection, especially during glycosylation coupling reactions . However, N-acylation is often encountered as an undesired side reaction during protection of the sugar portion of nucleosides that have an amino group on the nucleobase.…”

Nucleobase Protection of Deoxyribo‐ and Ribonucleosides

“…(4) The exocyclic amino group of cytidine and deoxycytidine can be directly acylated using activated esters (Igolen and Morin, 1980), acid chlorides (Mishra and Misra, 1986, and references therein), or alkyloxycarbonylbenzotriazoles (Himmelsbach et al, 1984). (5) Himmelsbach et al, 1984Pfleiderer et al, 1985Pfister and Pfleiderer, 1989 -Happ et al, 1987Hagen and Chládek, 1989Heikkilä and Chattopadhyaya, 1983Marugg et al, 1984Nagaich and Misra, 1989 4-nitrophenylethyloxycarbonyl Nyilas et al, 1988 G (N2); A (N6); C (N4) Brown et al, 1989Rao et al, 1987Tanimura et al, 1988Schaller et al, 1963Balgobin et al, 1981 Köster et al, 1981Sinha et al, 1993Boal et al, 1996 4-(tert-butyl)phenoxyacetyl diphenylacetyl 3,4-dichlorobenzoyl 3-methoxy-4-phenoxybenzoyl and removal of N-acyl protecting groups can also be achieved by enzymatic methods (Prasad and Wengel, 1996).…”

“…The original method by Ti et al () for installation of protecting groups has also been further simplified by eliminating the use of ammonium hydroxide during work‐up. Several approaches have been reported: (1) The exocyclic amino groups of cytidine and deoxycytidine were directly acylated using activated esters (Igolen & Morin, ), acid chlorides (Mishra & Misra, , and references therein), or alkyl oxycarbonyl benzotriazoles (Himmelsbach, Schulz, Trichtinger, Charubala, & Pfleiderer, ). (2) Site‐selective incorporation and removal of N ‐acyl protecting groups have also been achieved by enzymatic methods (Prasad & Wengel, ).…”

2′‐Hydroxyl‐Protecting Groups that are Either Photochemically Labile or Sensitive to Fluoride Ions

“…Accordingly, some of the 5′‐ O ‐(4,4′‐dimethoxytrityl)‐2′‐ O ‐(2‐nitrobenzyloxymethyl)uridine obtained in is converted directly into its corresponding cytidine derivative in , using the substitution procedure of Sung (). Its N4 amino group is then selectively benzoylated using pentafluorophenyl benzoate (Igolen and Morin, ) to give 5′‐ O ‐(4,4′‐dimethoxytrityl)‐2′‐ O ‐(2‐nitrobenzyloxymethyl)‐ N 4 ‐benzoylcytidine.…”