A solution of 8.9 g (49.6 mmol) of the product from Example 1, step 3 in 90 ml THF is cooled at −50° C. 28.6 ml (57.2 mmol) of a 2M solution of lithium diisopropylamide are added and the solution is allowed to heat to −10° C. After 15′ stirring at this temperature the deep colored solution is again cooled to −50° C. A solution of 11.6 g (49.8 mmol) of 1-benzyloxy-4-chloromethyl-benzene in 60 ml THF is dropped into the cooled solution. The system is allowed to heat to room temperature and stirred overnight. The solvent is evaporated and the residue that solidifies on cooling is stirred with ethyl ether and filtered. The residue is filtered through SiO2 eluting with dichloromethane. The yield is 3.75 g (20%).
