Published on Jan. 19, 2000 in Helvetica Chimica Acta volume .

DOI: 10.1002/(SICI)1522-2675(20000119)83:1<152::AID-HLC

Abstract:

As part of our studies on the structure of yeast tRNAfMet, we investigated the incorporation of N-{[9-(β-D-ribofuranosyl)-9H-purin-6-yl]carbamoyl}-L-threonine (t6A) in the loop of a RNA 17-mer hairpin. The carboxylic function of the L-threonine moiety of t6A was protected with a 2-(4-nitrophenyl)ethyl group, and a (tert-butyl)dimethylsilyl group was used for the protection of its secondary OH group. The 2′-OH function of the standard ribonucleotide building blocks was protected with a [(triisopropylsilyl)oxy]methyl group. Removal of the base-labile protecting groups of the final RNA with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and then with MeNH2 was done under carefully controlled conditions to prevent hydrolysis of the carbamate function, leading to loss of the L-threonine moiety.