Facile Stereospecific Synthesis of a-Anomeric 2'-Deoxynucleosides
摘要:
The coupling reaction of activated nucleobases, such as the sodium salts of N-benzoyladenine and 6-chloropurine and 2,4-bis-O-trimethylsilylthymine, with 1-alpha-chloro-2-deoxy-3,5-di-O-p-toluoylribofuranose (1) in a mixture of acetonitrile and tetrahydrufuran leads to the stereospecific formation of a-anomeric 2'-deoxynucleosides with satisfactory yields. The ratio of the distribution between the resulted alpha- and beta-stereoisomers was about 3:1 in each case. The method is simple and applicable to the preparation of both purine and pyrimidine alpha-2'-deoxynucleosides.
Investigation of stereoselectivities in the coupling reactions of 1-O-methyl-3, 5-di-O-p-toluoyl-2-deoxyribofuranoside with purines and pyrimidines
作者:Selvasekaran Janardhanam、Krishnan P. Nambiar
DOI:10.1016/s0040-4039(00)73064-4
日期:1994.5
Stereoselectivities in the coupling reaction between 1-O-methyl-3,5-di-O-p-toluoyl-2-deoxyribofuranoside and suitably protected purine and pyrimidine derivatives have been examined in acetonitrile with varying equivalents of SnCl4. The best result in alpha-nucleoside formation was obtained when the coupling reaction was carried out in the presence of ten equivalents of SnCl4.
Facile Stereospecific Synthesis of a-Anomeric 2'-Deoxynucleosides
The coupling reaction of activated nucleobases, such as the sodium salts of N-benzoyladenine and 6-chloropurine and 2,4-bis-O-trimethylsilylthymine, with 1-alpha-chloro-2-deoxy-3,5-di-O-p-toluoylribofuranose (1) in a mixture of acetonitrile and tetrahydrufuran leads to the stereospecific formation of a-anomeric 2'-deoxynucleosides with satisfactory yields. The ratio of the distribution between the resulted alpha- and beta-stereoisomers was about 3:1 in each case. The method is simple and applicable to the preparation of both purine and pyrimidine alpha-2'-deoxynucleosides.