Amino nucleosides, synthesis

A reaction which is analogous to the orthoester synthesis but which utilises glycosyl oxazolines affords means of synthesising, 2-trans-2 amino-2-deoxy-glycoside derivatives. Treatment of the gluco compomd (17) with phenol in the presence of toluene- -sulphonic acid thus gave the glycoside (18), and it was also utilised in a nucleoside synthesis 48). 

The Tsuji-Trost reaction, more commonly applied to carbocyclic nucleoside synthesis, has been used in the synthesis of famciclovir 21 (Scheme 5) <2000T4589>. Reaction of 2-amino-6-chloropurine with allylic carbonate 22 in the presence of Pd2DBA3 and bis(diphenylphosphino)ethane (DPPE) gave a 1 1 ratio of 23 to 24 after 1 h (DBA = dibenzylideneacetone). However, a ratio of >95 5 in favor of the thermodynamically favored N-9 isomer 23 was subsequently obtained upon further stirring, highlighting the reversibility of the reaction in this specific instance. 

Xylopyranoside, methyl 3-amino-3-deoxy-a-D-, deamination of, in nucleoside synthesis, 70... 

Cytidine and related pyrimidine nucleosides have also been synthesized by the mercuri procedure.198 In the case of the cytosine nucleoside, prior blocking of the amino function is necessary, in order to obtain a mercury derivative [(-V-acetylcytosine)mercury] adaptable for nucleoside synthesis. Reaction of one mole of LV with two moles199 of tri-O-benzoyl-D-ribofuran-... 

Park, K.H. et al. Enantioselective Synthesis of (IR,4S)-I-Amino-4-(hydroxy-methyl)-2-cyclopentene, a Precursor for Carbocyclic Nucleoside Synthesis. 2.4 1994 [165]... 

As a Chiral Starting Material in L Amino Sugar and l-Nucleoside Synthesis. The recent improved synthetic access to the (45)-aldehyde has facilitated non-natural sugar and nucleoside synthesis. Asymmetric synthesis of several L-amino sugars has been reported. Julia olefination of the (45)-aldehyde with the sulfone afforded the key olefin intermediate as a 4 1E/Z mixture, which was elaborated via Sharpless asymmetric dihydroxylation (SAD) and protecting group interchange to afford the protected 2-deoxy-2-amino-L-mannopyranose (eq 4). ... 

An illustration of the potential value of 2,3-unsaturated furanoid compounds, particularly in nucleoside synthesis, is the preparation, by way of an epoxy intermediate, of a crystalline compound claimed to be ethyl 3-amino-3-deoxy-DL-arabinofuranoside from racemic 2-eth-oxy-2,5-dihydro-5-(tetrahydropyranyloxymethyl)furan (41, R = OEt,... 

Adams SP, Kavka KS, Wykes EJ, Holder SB, Gallupi GT. Hindered dialkyl-amino nucleoside phosphate reagents in the synthesis of two DNA 51-mers. 

Benzylsulfonyl as N-Blocking Group in Amino Sugar Nucleoside Synthesis, M. L. Wolfrom and R. Wurmb,/. Org. Chem., 30, 3058-3061 (1965). 

Staudinger reaction of azido nucleosides for the synthesis of amino nucleosides... 

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