Abstract: Quinestrol was used as the lead compound for studies on the new steroidal contraceptives for early pregnancy. The 11 α-hydroxyl and 11 α-methoxyl derivatives of quinestrol were synthesized. △⁹⁽¹¹⁾-Estrone was treated with cyclopentyl bromide and potassium carbonate to form the cyclopentyl ether (2). Hydroboration—oxidation of the ethylene ketal of (2) with B₂H₆—H₂O₂ and chromatographic separation on silica gel gave 11 α-hydroxide (4) and small amount of 11 β-hydroxide and compound (3). (4) was methylated with NaH/DMSO and methyl iodide to afford (5), The 11 α-methoxy-quinestrol (7) was obtained when. (5) was hydro- lized with 5% hydrochloric acid and then ethynylated with ethynyl lithium. While the 11 α-hydroxy-quinestrol (9) was obtained when (4)was treated with 10% hydrochloric acid and then ethynylated with ethynyl lithium. The configurations of the target compounds and their respective intermediates were confirmed by IR, MS, ¹HNMR and elemental analysis. Preliminary pharmacological result on mice showed that 11 α-hydroxy and 11 α-methoxy derivatives of quinestrol did not possess significant antifertility activity.