[Mg].II.[CH2:4](Cl)[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.[CH2:12]([O:19][C:20]1[CH:21]=[C:22]([CH:25]=[CH:26][CH:27]=1)[C:23]#N)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.Cl.C([O:31]CC)C>>[CH2:12]([O:19][C:20]1[CH:21]=[C:22]([C:23]([CH2:4][C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=2)=[O:31])[CH:25]=[CH:26][CH:27]=1)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1A suspension of magnesium turnings (9 g) in dry diethyl ether (100 mL) containing a few crystals of iodine is treated with a solution of benzyl chloride (22.8 g) in diethyl ether (150 mL) at such a rate in the form of to maintain gentle reflux. After the addition is complete, the mixture is treated with 3-benzyloxybenzonitrile (12.7 g) and heated to reflux for 5 hours. The mixture is then treated with hydrochloric acid (1 N) until it is at pH 1, and stirring is continued for 1 hour at ambient temperature. The reaction mixture is separated and the aqueous layer extracted with diethyl ether (3×100 mL). The combined organic extracts are washed with water (3×100 mL), dried over magnesium sulphate and concentrated under reduced pressure. The resulting residue is recrystallised from methanol, to give benzyl 3-benzyloxyphenyl ketone (14.8 g), in the form of a white solid, m.p. 58-60° C. [Elemental analysis:- C,76.2; H,4.99%; Calculated:- C,76.28;H,4.99%].
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