Fluoroadenosine 5 -deoxy-5 -, synthesis

Synthesis of 2 -Deoxy-2 -a-fluoroadenosine Using a Protection Strategy with 3and 5 -Hydroxyl Groups... 

FddA from 2 -Deoxy-2 -a-fluoroadenosine Until recently, the introduction of a fluoro group to the P-side of C-2 has been quite difficult, as described earlier. Accordingly, a novel strategy that involves the inversion of C-2 of 2 -deoxy-2 -a-fluororiboside to its 2 -p-fluoro epimer was developed by Marquez and co-workers (see Scheme 7.12). In their synthesis, A -benzoyl-2 -deoxy-2 -a-fluoroadenosine (43a) was converted to 3 -0-... 

Maruyama, T., Utzumi, K., Sato, Y. and Richman, D. D. (1994) Synthesis and anti-HIV activity of 2-substituted 2 -deoxy-2 -fluoroadenosines. Nucleosides Nucleotides, 13, 1219-1230. 

A convenient synthesis of 5 -deoxy-2-fluoroadenosine from guanosine has been reported. Ring-opening of l-(2,3-anhydro-P-D-lyxofuranosyl)-cytosine and -uracil with ammonium bromide, iodide, azide, and thiocyanate in refluxing ethanol has been used to prepare l-(3-deoxy-3-halogeno-P-D-arabinofuranosyl)-... 

Some 4, S -unsaturated-S -fluoroadenosine nucleosides are described in Chapter 20 as well as some purine nucleosides containing the 2 -deoxy-2 fluoro- -D-arabinofuransoyl moiety. A number of dideoxymonofluoro- and dideo difluoro-a-D-glucopyranosyl phosphates have been prepared in order to study their relative rates of acid hydrolysis. The synthesis of a fluorinated 3-deoj -D-glyceric add phosphonate is discussed in Chapter 17 and the conversion of a l,3-anhydro-2-deojty- 2,2-difluoro-D-hexose derivative into a hydrolytically stable thromboxane A2 mimic is covered in Chapter 24. 

A rapid synthesis of 2 -deoxy-2 -fluoroadenosine Involves the use of DAST on a suitably protected ara-A derlvative.85 A number of purine nucleosides containing the 2 -deo3qr-2 -fluoro-p-D-arabinofuranosyl moiety (48) have been prepared from glycosyl bromide and purine bases the guanosine analogue (48,... 

For the synthesis of 2 -deoxy-2 -fluoroadenosine (2a) from ara-A, smaller 3, 5 - protecting groups (such as methoxymethyl, benzyl, or methojgrbenzyl groups) appear to be more favorable for ara-A to assume the presumably favored C-3 endo conformation than the trityl groups (which promote C-3 endo to C-2 endo conformational shift). In order to prepare 3, 5 -protected ara-A, 3, 5 -0-(l,l,3,3-tetraisopropyl)disiloxanyl-N -benzoyladenosine (54, Scheme 10) was triflylated, and the... 

We also synthesized 3 -fluoroadenosine. In our case, the starting material was again 2, 5 -di-0-trityl-N -trityladenosine 32 (Scheme 5), which had already served as the starting material for the synthesis of 2 -deoxy-2 -fluoroadenosine (2a, Scheme 11). 

An improved synthesis of 2 -deoxy-2 -fluoroadenosine has been described, involving a sequence of two inversions of configuratkMi at C-2 of an adenosine derivative, whilst the 2 -deoxy-2 -fluoroderivatives of a wide range of purine nucleosides have been made by glycosyl transfn 6tMn 2 -deoxy-2 -fluorouridine uring diymidine phosphorylase and purine nucleoside phosphc lase. ... 

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