A compound of Formula (1), is disclosed wherein P1 and P2 are alcohol protecting groups or 1,3-diol protecting group, R is selected from: wherein R4a 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, CF3, halo and NO2 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.