Syntheses and some features of five new cyclohexane-1,3-dicarboxylates with multiple stereogenic centers

• Published in: Journal of molecular structure 2013-01, Vol.1032 (30), p.83-87
• Main Authors: Ismiyev, Arif M., Maharramov, Abel M., Aliyeva, Rafiga A., Askerov, Rizvan K., Mahmudov, Kamran T., Kopylovich, Maximilian N., Naïli, Houcine, Pombeiro, Armando J.L.
• Format: Article
• Language: English
• Subjects: Carbonyls; condensation; Condensing; Conjugation; Constants; Correlation analysis; Derivatives; electrospray ionization mass spectrometry; Esters; NMR spectroscopy; nuclear magnetic resonance spectroscopy; Stereogenic center creation; Substituted cyclohexane; Transformations; X-radiation
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2012.08.006

► A series of 5 new cyclohexane-1,3-dicarboxylates are synthesized. ► A new stereogenic center is introduced to the starting materials upon the synthesis. ► Correlations between the substituent constants and δOH or δNH NMR chemical shifts are analyzed. The condensation of diethyl 4-hydroxy-4-methyl-6-oxo-2-(4-substitutedphenyl)-cyclohexane-1,3-dicarboxylates and N′-(2-chloropropyl)ethane-1,2-diamine leads to diethyl 1-(2-chloropropyl)-9-hydroxy-9-methyl-7-phenyl-1,4-diazaspiro[4.5]decane-6,8-dicarboxylate (2) and its para-substituted methyl (1), chloro (3), bromo (4), and nitro (5) derivatives with a new stereogenic center, which were fully characterized by elemental analysis, ESI-MS, IR, 1H and 13C NMR spectroscopies and X-ray single-crystal analysis (for 2). The condensation reaction is regioselective, only cyclohexanone carbonyl moiety undergoes the transformation, leaving the β-keto ester carbonyls unreacted. Withing the compounds 1–5, the increase in the Hammett’s σp, related normal σpn, inductive σI, negative σp- and positive σp+ polar conjugation and Taft’s σpo substituent constants generally leads to the corresponding drift of δOH and δNH NMR chemical shifts to lower field.