A process for the synthesis of trans-fused γ-lactones having Formula (IV) from substituted cyclic ketones having Formula (I). A diastereoselective synthesis of (±)-epianastrephin (1) (wherein: R1 is ethenyl, R2 and R3 is methyl, and n is 1), (±)-anastrephin (2) (wherein: R2 is ethenyl, R1 and R3 is methyl and n is 1), and analogs thereof (wherein: R1 is H, C1-5 alkyl, C2-6 alkenyl or C2-6 alkynyl, R2 is H, C1-5 alkyl, C2-6 alkenyl or C2-6 alkynyl, R1 and R2 together with the carbon atom they are attached form a C3-6 cycloalkyl ring, R3 is C1-5 alkyl and n is 0-2):