Confirmation of the Carbon Chemical Shifts of Ethylenic Carbon Atoms in Methyl Ricinoleate and Methyl Ricinelaidate

Abstract
The carbon chemical shifts of the ethylenic carbon atoms of methyl ricinoleate (12-hydroxy-9-cis-octadecenoate) are 133.32, C-9; 125.28, C-10 and those of methyl ricinelaidate (12-hydroxy-9-trans-octadecenoate) are 134.56, C-9 and 125.97, C-10. The shift values were confirmed by double irradiation (spin decoupling) and 1H-13C COSY nuclear magnetic resonance techique.