Synthesis and NMR spectral study of some t(3)-aryl-r(2),c(4)-bisethoxycarbonyl-t(5)-hydroxy-c(5)-methylcyclohexanones

K Pandiarajan; R T Sabapathy Mohan; R Gomathi; G Muthukumaran

doi:10.1002/mrc.1568

Synthesis and NMR spectral study of some t(3)-aryl-r(2),c(4)-bisethoxycarbonyl-t(5)-hydroxy-c(5)-methylcyclohexanones

Magn Reson Chem. 2005 May;43(5):430-4. doi: 10.1002/mrc.1568.

Authors

K Pandiarajan¹, R T Sabapathy Mohan, R Gomathi, G Muthukumaran

Affiliation

¹ Department of Chemistry, Annamalai University, Annamalainagar 608 002, India. profkprajan@yahoo.co.in

PMID: 15751022
DOI: 10.1002/mrc.1568

Abstract

Six t(3)-aryl-r(2),c(4)-bisethoxycarbonyl-t(5)-hydroxy-c(5)-methylcyclohexanones (6-11) were synthesized by condensing ArCHO (Ar = Ph, p-O(2)NC(6)H(4), p-CH(3)OC(6)H(4), p-ClC(6)H(4), m-O(2)NC(6)H(4) and m-C(6)H(5)O(6)H(4)) with ethyl acetoacetate in the presence of methylamine and their (1)H and (13)C NMR spectra were recorded. (1)H-(1)H COSY and NOESY spectra were recorded for 6 and 7 and also HSQC and HMBC spectra for 6 and 8. Elemental analysis was carried out for all compounds. The mass spectrum was recorded for 8. All analytical data are consistent with the proposed molecular formulae. Analysis of NMR spectral data suggests that these compounds largely adopt chair conformations with the hydroxyl group occupying an axial orientation and all the other substituents occupying equatorial orientations. Long-range coupling (2-3 Hz) between the OH proton and the axial methylene proton at C-6 is observed in 6, 7, 8 and 11.