A NOVEL CHIRAL BUILDING-BLOCK WITH NEOPENTANE FRAMEWORK FOR SYNTHESIS - CHEMOENZYMATIC PREPARATION OF (R)-CH3C(CH2OSO2CF3)(CH2CL)(CH2BR)

The pig liver esterase (PLE) catalysed hydrolysis of the prochiral malonic ester (BzlOCH(2)) (Me)C(COOMe)(2) (1) leads to its chiral monoester 2 in selectivities up to 81% ee. Compound 2 is an ideal entry point for the enantioselective synthesis of 1,1',1''-substituted neopentanes CH3C(CH(2)X)- (CH2Y)(CH(2)Z) with three different leaving groups, X, Y, and Z. CH3C(CH2OSO2CF3)(CH2Br) (CH2Cl) (8) is a versatile reactive building block for the asymmetric synthesis of compounds containing the neopentane-C-5 skeleton.