Enzymatic synthesis of chiral menthyl methacrylate monomer by pseudomonas cepacia lipase catalysed resolution of (±)-menthol

Optically active methacrylate ester of (−)-menthol was synthesised by enantioselective transesterification of (±)-menthol using pseudomonas cepacia lipase (Lipase-PS) as a biocatalyst. Effect of change in various reaction parameters such as amount of catalyst, type of acyl donor, solvent and temperature on the conversion as well as enantioselectivity was studied. Methyl methacrylate, vinyl methacrylate and 2,3-butanedione mono-oxime methacrylate were used as acylating agents. Oxime methacrylate gave better conversion as compared to other acyl donors used in the present study. Diisopropylether (DIPE) was found to be the most suitable solvent. (−)-Menthyl methacrylate was obtained with 96% yield and 98% enantiomeric excess.