Nucleosides and nucleotides. Part 212: Practical large-scale synthesis of 1-(3-C-ethynyl-β-d-ribo-pentofuranosyl)cytosine (ECyd), a potent antitumor nucleoside. Isobutyryloxy group as an efficient anomeric leaving group in the Vorbrüggen glycosylation reaction
作者:Makoto Nomura、Tsutomu Sato、Masato Washinosu、Motoaki Tanaka、Tetsuji Asao、Satoshi Shuto、Akira Matsuda
DOI:10.1016/s0040-4020(01)01249-2
日期:2002.2
A practical synthetic route to the antitumor nucleoside, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd, 1) from 1,2-O-isopropylidene-D-xylofuranose (3) has been developed. Since most of the compounds were obtained as crystals, the target ECyd was prepared without any chromatographic purification in 31% overall yield from compound 3. The isobutyryloxy group was found to be an effective leaving group at the anomeric position of the 3-beta-C-ethynyl glycosyl donors in the key Vorbruggen glycosylation reaction. Using a similar procedure without chromatographic purification, the uracil congener EUrd [1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)uracil (2), which also has a potent antitumor effect, was synthesized from 3 in 39% overall yield. (C) 2002 Elsevier Science Ltd. All rights reserved.