Chemo-Enzymatic Synthesis of Thymidine13C-Labelled in the 2′-Deoxyribose Moiety

Abstract

A synthesis of [3′,4′‐13C2]thymidine (1) is described in which [13C2]acetic acid (2) is converted into the nucleoside in twelve steps with 9% overall yield. D‐2‐Deoxyribose‐5‐phosphate aldolase (DERA, EC 4.1.2.4) and triosephosphate isomerase (TPI, EC 5.3.1.1) are used for the stereocontrolled formation of D‐[3,4‐13C2]‐2‐deoxyribose‐5‐phosphate (8) from [2,3‐13C2]dihydroxyacetone monophosphate (DHAP, 7) and acetaldehyde in 80% yield. The route permits the introduction of isotopically enriched carbon atoms at any position or combination of positions in the furanose ring and the product can be coupled with any of the four naturally occurring base moieties.

Synthesis of [1′,2′,5′,2-13C4]-2′-Deoxy-D-adenosine by a Chemoenzymatic Strategy to Enable Labelling of Any of the 215 Carbon-13 and Nitrogen-15 Isotopomers

“…[10] In an attempt to improve upon this method for the preparation of purine-2Ј-deoxynucleosides, the procedure originally developed for the synthesis of pyrimidine analogues was applied. [3] In this route, depicted at the top of Scheme 3, intermediate 4 is formed by migration of the phosphate group from the 5-to the 1-position in 2-deoxyribose. Subsequently, coupling of a nucleobase results in liberation of inorganic phosphate.…”

“…The slightly lower enrichment of this position (96%) was due to scrambling of 3% of the 13 C isotope to the 3Ј-position. [1] The NMR results were independently confirmed by the high-resolution mass spectra of the final products 1a and 2a.…”

“…Compound 4a is generated from [1Ј,2Ј,5Ј-13 C 3 ]-thymidine (3a), which is an attractive starting material, since its 2Ј-deoxyfuranoside ring is labelled efficiently. [1] The addition of a catalytic amount of phosphate and TP ensure the formation of 4a. In this reaction the phosphate displaces the thymine and the α-anomeric phosphate ester arises (see Scheme 1).…”

“…[1,2] In line with our continuous effort to develop regio-and stereocontrolled methods without the need for protection and deprotection steps, the procedure was improved by an one-pot, two-step enzymatically catalysed coupling between α-2-deoxy--ribose-1-phosphate and thymine. [3] Deoxyribose-1-phosphate was obtained, in situ, from 2-deoxy--ribose-5-phosphate by means of a migration of the phosphate group from the C5-to the C1-position of the sugar ring. This method, which allows substitution of all carbon and nitrogen positions of pyrimidine 2Ј-deoxynucleosides by stable isotopes, shortened the previous classical scheme by six steps.…”

“…In this paper we describe a procedure based on the combination of two methods: 1) to generate the 1-phosphate 4 by enzymatic phosphorylation of thymidine (Scheme 1) [4] and 2) to synthesise all labelled isotopomers of the sugar ring by an enzymatic aldol condensation of acetaldehyde and 2-deoxyribose-5-phosphate. [1] In addition, we describe here a synthetic route to all isotopomers of adenine. In spite of the fact that literature methods to incorporate isotopes both in five-and in six-membered rings are known, schemes that allow synthesis of all the 2 10 isotopomers are still lacking.…”