130144-85-3Relevant articles and documents
2-Deoxy-3-C-(hydroxymethyl)-D-pentofuranose Derivatives: Stereoselective Synthesis and Conversion into a Novel Class of Nucleoside Analogues
Scheuer-Larsen, Claus,Pfundheller, Henrik,Wengel, Jesper
, p. 7298 - 7303 (1995)
Oxidation of pure anomers of 5-O-monoprotected methyl 2-deoxy-D-ribofuranosides 3-6 followed by Lombardo methylenation afforded the novel 3-C-methylene pentofuranosides 11 - 14.Subsequent osmium tetraoxide-catalyzed dihydroxylations of 11, 13, and 14 afforded a mixture of erythro- and threo-configured 3-C-hydroxymethyl furanosides 15/16, 18/19, and 20/21, respectively.However, analogous dihydroxylation of 5-O-(4-phenylbenzoyl)-protected β-anomer 12 proceeded with complete stereoselectivity to give 3-C-(hydroxymethyl)-β-D-erythro pentofuranoside 17 in 76percent yield.Conversion of 17 to the corresponding primary tosylate 22, followed by base-catalyzed nucleophilic attack by the nucleobases adenine and thymine, afforded after deprotection compounds 25 and 26, respectively, as the first examples of a novel class of nucleoside analogues.
Products Generated by Amine-Catalyzed Strand Cleavage at Apurinic/Apyrimidinic Sites in DNA: New Insights from a Biomimetic Nucleoside Model System
Gates, Kent S.,Haldar, Tuhin,Housh, Kurt,Jha, Jay S.,Nel, Christopher,Peters, Daniel
, p. 203 - 217 (2022/02/25)
Abasic sites are common in cellular and synthetic DNA. As a result, it is important to characterize the chemical fate of these lesions. Amine-catalyzed strand cleavage at abasic sites in DNA is an important process in which conversion of small amounts of the ring-opened abasic aldehyde residue to an iminium ion facilitates β-elimination of the 3′-phosphoryl group. This reaction generates a trans-α,β-unsaturated iminium ion on the 3′-terminus of the strand break as an obligate intermediate. The canonical product expected from amine-catalyzed cleavage at an AP site is the corresponding trans-α,β-unsaturated aldehyde sugar remnant resulting from hydrolysis of this iminium ion. Interestingly, a handful of studies have reported noncanonical 3′-sugar remnants generated by amine-catalyzed strand cleavage, but the formation and properties of these products are not well-understood. To address this knowledge gap, a nucleoside system was developed that enabled chemical characterization of the sugar remnants generated by amine-catalyzed β-elimination in the 2-deoxyribose system. The results predict that amine-catalyzed strand cleavage at an AP site under physiological conditions has the potential to reversibly generate noncanonical cleavage products including cis-alkenal, 3-thio-2,3-dideoxyribose, and 2-deoxyribose groups alongside the canonical trans-alkenal residue on the 3′-terminus of the strand break. Thus, the model reactions provide evidence that the products generated by amine-catalyzed strand cleavage at abasic sites in cellular DNA may be more complex that commonly thought, with trans-α,β-unsaturated iminium ion intermediates residing at the hub of interconverting product mixtures. The results expand the list of possible 3′-sugar remnants arising from amine-catalyzed cleavage of abasic sites in DNA that must be chemically or enzymatically removed for the completion of base excision repair and single-strand break repair in cells.
Synthesis of medium-ring lactones via tandem methylenation/Claisen rearrangement of cyclic carbonates
Anderson, Edward A,Davidson, James E.P,Harrison, Justin R,O'Sullivan, Paul T,Burton, Jonathan W,Collins, Ian,Holmes, Andrew B
, p. 1943 - 1971 (2007/10/03)
The conversion of vinyl-substituted 6- and 7-membered cyclic carbonates into 8- and 9-membered medium-ring lactones has been achieved in good yield using dimethyltitanocene in toluene at reflux. The reaction proceeds by initial formation of a ketene acetal which undergoes subsequent in situ Claisen rearrangement to provide the corresponding lactones. The preparation of the cyclic carbonates is carried out under basic conditions and hence this methodology complements our existing selenium-based methodology for the synthesis of medium-ring lactones.
