p-Toluenesulfonic acid → (S)alpha-[(2S)(6-bromo-hexahydro-3,5-methano-2H-cyclopenta[b]furan-2-yl)-oxy]-3-phenoxy-benzene-acetonitrile

A solution of 2.19 g of the product of Step B in 50 ml of methylene chloride was added to a refluxing mixture of 2.93 g of (R,S)α-cyano-3-phenoxy-benzyl alcohol, 100 ml of methylene chloride and 300 mg of p-toluene sulfonic acid and the mixture was refluxed for another 15 minutes and then returned to room temperature. The mixture was washed with water, dried, vacuum filtered and evaporated to dryness under reduced pressure. The 4.34 g of the (R,S)α-[(2S)(6-bromohexahydro-3,5-methano-2H-cyclopenta[b]furan-2-yl)-oxy]-3-phenoxy-benzene acetonitrile were chromatographed over silica gel and eluted with a 9-1 hexane-ethyl acetate mixture to obtain the (S)α-isomer melting at 65° C. and having a specific rotation of [α]D20 =+110° (c=0.5% in dimethylformamide) and the (R)α-isomer with a specific rotation of [α]D20 =+108.5° (c=0.4% in dimethylformamide).