Transformation of Some tRNA “Wobble Uridines”: To their 2-Thioanalogues

Abstract

2',3'-O-Isopropylidene-5-[(N-trifluoroacetyl)methoxycarbonylmethylaminomethyl]uridine (5) and 2',3'-O-isopropylidene-5-ethoxycarbonylmethoxyuridine (6) have been prepared using as the substrates 2',3'-O-isopropylidene-5-chloromethyluridine (11) and 2',3'-O-isopropylidene-5-hydroxyuridine (8), respectively. The transformation of 5 and 6 into respective 2,5'-anhydro-nucleosides 16 and 10 followed by treatment of 16 and 10 with liquid hydrogen sulphide/pyridine system produces 2',3'-O-isopropylidene-5-[(N-trifluoroacetyl)methoxycarbonylmethylaminomethyl]-2-thiouridine (17) and 2',3'-O-isopropylidene-5-ethoxycarbonylmethoxy-2-thiouridine (18). The acid catalysed methanolysis of 6 and 18 yields 5-methoxycarbonylmethoxyuridine (4) and its 2-thioanalogue 4a, while refluxing of 5 and 17 with 50% acetic acid gives 5-[(N-trifluoroacetyl)methoxycarbonylmethylaminomethyl]uridine (2) and its 2-thioanalogue 2a. © 1987, Walter de Gruyter. All rights reserved.