The known estradiol derivative (I) was oxidized with Jones reagent to give the keto acid (II). After activation of (II) as the mixed anhydride with isobutyl chloroformate, condensation with N-butyl-N-methylamine yielded amide (III). Addition of the lithium acetylide of 2-(propinyloxy)tetrahydropyran (IV) to the keto group of (III) furnished the corresponding propargyl alcohol (V) with concomitant cleavage of the benzoate ester. The triple bond of (V) was then subjected to catalytic hydrogenation using a mixture of Pd/C and Pd/CaCO3 as the catalyst to produce the saturated compound (VI). After cleavage of the tetrahydropyranyl protecting group of (VI) with amberlyst-15 ion-exchange acid resin in MeOH, the deprotected alcohol was oxidized and cyclized with Jones reagent to yield the desired gamma-lactone