Synthesis of dimer and oligomers from (R)-methyl hydnocarpate

We report synthesis and characterization of dimer and oligomer acids from c haulmoogra oil. (R)-Methyl hydnocarpate (methyl ester of the major fatty ac id component of chaulmoogra oil) was brominated to give threo-2,3-dibromocy clopentane-1-methyl undecanoate. Formation of two diastereoisomers, viz., t hreo-2(R),3(R)-dibromocyclopentane-1(R)-methyl undecanoate and threo-2(S),3 (S)-dibromocyclopentane-(R)-1-methyl undecanoate, was observed. Dehydrobrom ination of bromo derivatives using alcoholic KOH gave a cyclopentadiene der ivative as intermediate, which underwent Diels-Alder reaction to give dimer and oligomer fatty acids. The products were characterized by ultraviolet, direct exposure probe-mass spectroscopy, H-1 nuclear magnetic resonance (NM R), and C-13 NMR spectroscopic techniques.