Inosine 2-deoxy deriv

Figure 3.14 Structures of common nucleosides whose acid-catalysed hydrolysis has been studied. Adenosine, guanosine and cytidine are three of the four common nucleosides in RNA and their 2 -deoxy derivatives in DNA, whereas uridine is found only in RNA and 2 -deox5hh5midine in DNA. Psicofuranine is an antibiotic and is not a common constituent of nucleic acids. Inosine is a commonly used substrate in investigations of enzymic ribosyl transfer.

The same yeast can also be used to prepare 3 -0-p-D-galactosyl derivatives of adenosine and inosine. Further details of the structure of adenophostins A and B have been reported.(See Vol. 27, Chap. 19, ref. 52). The cytotoxic and antimicrobial nucleoside shimofuridin A 7 has been isolated from a marine tunicate. References to AZT derivatives and to 2 -deoxy-2 -fluorouridine derivatives are made in Chapter 20. 

Syntheses of the 2, 3 -0-isopropylidene-8,5 ( S)-cycloderivatives of adenosine and guanosine have been achieved by selenium dioxide oxidation of the 5 -deoxy-8,5 -cyclonucleosides to give the 5 -oxo compounds, followed by stereoselective reduction with sodium borohydride. The 8,5 -(R) series was obtained by inversion of the (5) isomer via the 5 -mesyloxy derivative. Hydrolytic deamination of the adenosine derivatives gave the inosine counterparts. Their c.d. spectra reflected the chirality at the 5 -position. ... 

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