- Tosvinyl and besvinyl as protecting groups of imides, azinones, nucleosides, sultams, and lactams. Catalytic conjugate additions to tosylacetylene
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The use of the 2-(4-methylphenylsulfonyl)-ethenyl (tosvinyl, Tsv) group for the protection of the NH group of a series of imides, azinones (including AZT), inosines, and cyclic sulfonamides has been examined. The Tsvprotected derivatives are obtained in excellent yields by conjugate addition to tosylacetylene (ethynyl p-tolyl sulfone). The stereochemistry of the double bond can be controlled at will: with only 1 mol % of Et3N or with catalytic amounts of NaH, the Z stereoisomers are generated almost exclusively, while the E isomers are obtained using a stoichiometric amount of DMAP. Analogous phenylsulfonylvinyl-protected groups (with the besvinyl or Bsv group instead of Tsv) are obtained stereospecifically by reaction with (Z)- or (E)-bis(phenylsulfonyl)ethene. For lactams and oxazolidinones, this last method is much better. The Tsv and Bsv groups are stable in the presence of non-nucleophilic bases and to acids. They can be removed highly effectively via a conjugate addition-elimination mechanism using pyrrolidine or sodium dodecanethiolate as nucleophiles.
- Petit, Elena,Bosch, Llus,Font, Joan,Mola, Laura,Costa, Anna M.,Vilarrasa, Jaume
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p. 8826 - 8834
(2015/01/08)
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- Synthesis and antineoplastic activity of 3'-azido and 3'-amino analogues of pyrimidine deoxyribonucleoside
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Several new 3'-azido and 3'-amino nucleosides (8, 9, 12, and 13) have been synthesized and their biological activities evaluated. Among them, 3'-amino-2',3'-dideoxycytidine (13) was found to exhibit potent cytotoxic activity against both L1210 and S-180 cells in vitro with an ID50 of 0.7 and 4.0 μM, respectively. Furthermore, 13 has also shown antitumor activity against L1210 tumor bearing mice with a T/C x 100 value of 283.
- Lin,Mancini
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p. 544 - 548
(2007/10/02)
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