Nucleotides, Part LXIII, New 2-(4-Nitrophenyl)ethyl(Npe)- and 2-(4-Nitrophenyl)ethoxycarbonyl(Npeoc)-Protected 2′-Deoxyribonucleosides and Their 3′-Phosphoramidites - Versatile Building Blocks for Oligonucleotide Synthesis

Autor: Holger Lang, Margarete Gottlieb, Frank Himmelsbach, Wolfgang Pfleiderer, Ramamurthy Charubala, Michael Schwarz, Silke Farkas, Bernd S. Schulz
Rok vydání: 1999
Předmět:
Zdroj: Helvetica Chimica Acta. 82:2172-2185
ISSN: 1522-2675
0018-019X
DOI: 10.1002/(sici)1522-2675(19991215)82:12<2172::aid-hlca2172>3.0.co;2-r
Popis: A series of new base-protected and 5′-O-(4-monomethoxytrityl)- or 5′-O-(4,4′-dimethoxytrityl)-substituted 3′-(2-cyanoethyl diisopropylphosphoramidites) and 3′-[2-(4-nitrophenyl)ethyl diisopropylphosphoramidites] 52 – 66 and 67 – 82, respectively, are prepared as potential building blocks for oligonucleotide synthesis (see Scheme). Thus, 3′,5′-di-O-acyl- and N 2,3′-O,5′-O-triacyl-2′-deoxyguanosines can easily be converted into the corresponding O6-alkyl derivatives 6, 8, 10, 12, 14, and 16 by a Mitsunobu reaction using the appropriate alcohol. Mild hydrolysis removes the acyl groups from the sugar moiety (→ 9, 11, 13, 15, and 19 (via18), resp.) which can then be tritylated (→ 38 – 42) and phosphitylated (→ 57 – 61) in the usual manner. N 2-[2-(4-nitrophenyl)ethoxycarbonyl]-substituted and N 2-[2-(4-nitrophenyl)ethoxycarbonyl]-O6-[2-(4-nitrophenyl)ethyl]-substituted 2′-deoxyguanosines 5 and 7, respectively, are synthesized as new starting materials for tritylation (→ 28, 35, and 37) and phosphitylation (→ 54, 56, 70, and 78). Various O4-alkylthymidines (see 20 – 24) are also converted to their 5′-O-dimethoxytrityl derivatives (see 43 – 47) and the corresponding phosphoramidites (see 62 – 66 and 79 – 82).
Databáze: OpenAIRE
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