Anhydrous 2-(N-pyrrolidinyl)-ethyltriphenylphosphonium bromide (10 g, 45 mmole), 48 mmole of n-butyl lithium in hexane, and 2-bromo-6,11-dihydrodibenz [b,e1-oxepin-11-one (5 g, 35 mmole) were reacted in 300 mL dry tetrahydrofuran by the procedure in Example 1, Step a. This provided the pure Z-isomer (1.76 g) as a light brown solid, mp 108°-109° C.. pmr (DMSO-d6) δ: 7.28-7.50 (m, 6H, aromatic H); 6.80 (d, J=8.8 Hz, 1H, H4); 5.82 (t, 1H, HC=); 5.20 (s, 2H, ArCH2O); 3.29 (m, 2H, NCH2C=); 2.50 (m, 4H, 2NCH2); 1.70 (m, 4H, 2CH2).
