Synthesis of cyclobutane nucleoside analogues 3: Preparation of carbocyclic derivatives of oxetanocin |
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Authors: | Muhammad Murtaza Hassan Ayat Yaseen Abdelaziz Ebead Gerald Audette |
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Institution: | 1. Department of Chemistry, York University, Toronto, Ontario, Canada;2. Chemistry, Arish University, El Arish, Egypt |
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Abstract: | AbstractA 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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Keywords: | Oxetanocin nucleoside analogs cyclobutanone cyclobutanol 6-chloropurine charge delocalization of 6-chloropurine anion photochemistry |
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