合成路线1

Claisen condensation of 3-O-benzylestrone (I) with ethyl formate in the presence of NaH afforded the 16-hydroxymethylene derivative (II), which was further converted to enol ether (III) by alkylation with ethyl iodide. Stereoselective ketone reduction of (III) with LiAlH4 gave the 17-beta alcohol (IV), which was esterified with Ac2O in pyridine to provide acetate (V). Acid hydrolysis of the enol ether of (V) produced the 16-alpha aldehyde (VI), and subsequent Jones oxidation furnished the carboxylic acid (VII). After basic hydrolysis of the acetate ester of (VII) to yield (VIII), its O-benzyl protecting group was removed by hydrogenolysis over Pd/C, yielding diol (IX). Finally, Fischer esterification with 2-fluoroethanol in the presence of p-toluenesulfonic acid gave rise to the title fluoroethyl ester.