Nucleosides of Unsaturated Sugars, Aldosuloses and Uronic Acids

Nucleosides of Unsaturated Sugars, Aldosuloses and Uronic Acids 

As in previous volumes, 2, 3 -didehydro-2, 3 -dideoxyfuranosyl derivatives are discussed in Section 4, together with their saturated analogues. 

Compounds of type 104 have been prepared by reaction of 3,4-bis-0-(p-nitrobenzoyl)-D-xylal with nucleobases in refluxing DMF, followed by deacylation. The conformations of these analogues have been studied in some detail.An alternative synthesis has been described of the alkyne 105 (see Vol.25, p. 258-9 for the earlier route), involving reaction of a protected 5 -aldehyde with Ph3P=CBr2.  

The thymine nucleoside 106 has been prepared by coupling of silylated thymine with the glycosyl bromide (Vol.18, p.84-85), made by a photobromination procedure. 

Some glucuronate nucleosides of barbiturates have been reported,as has the analogue 107 of a thymidine dinucleotide, which was incorporated into oligonucleotides.  

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