Patent ID: 8759518

Claim:
A compound of Formula (1), wherein P 1 and P 2 are alcohol protecting groups or 1,3-diol protecting group, R is selected from: wherein R 4 a is selected from alkyl, aryl, arylalkyl and cycloalkyl, Rc is selected from H, alkyl, aryl, alkaoxy, haloalkyl, monohaloalkyloxy, and dihaloalkyloxy, Rd is selected from alkyl, aryl, arylalkyl, CF 3 , halo and NO 2 and X is selected from O, N—H, N-alkyl and S, Ra and Rb are same or different and each represents hydrogen, an alkyl group of 1 to 12 carbon atoms, an aryl group of 6 to 12 carbon atoms, or an aralkyl group of 7 to 12 carbon atoms.