Hassan MM, Yaseen A, Ebead A, Audette G, Lee-Ruff E. Synthesis of cyclobutane nucleoside analogues 3: Preparation of carbocyclic derivatives of oxetanocin.
NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2018;
37:518-531. [PMID:
30188772 DOI:
10.1080/15257770.2018.1500697]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A synthesis of cyclobutene nucleoside analogs in which the nucleobase is tethered by a methylene group is described. The coupling of 6-chloropurine with 3-hydroxymethyl-cyclobutanone proceeds via its triflate to give both N-7 and N-9 regioisomers with relative yields corresponding to the calculated charge distribution of the 6-chloropurinyl anion. The stereoselective reduction of the N-alkylated ketones yielded quantitatively one stereoisomer in each case. The structural assignments were based on spectroscopic data and single crystal X-ray diffraction. Attempts to photoexcite the N-7 and N-9 ketones in order to promote ring-expansion did not ensue. Preliminary evidence suggests a photodecarbonylation to cyclopropanes took place.
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