propyl (E)-5-(1-cyanoethylidene)-5,11-dihydrobenzooxepino[3,4-b]pyridine-2-carboxylate 、 propyl (E)-11-cyanocyclopropylmethylene-6,11-dihydrodibenzo[b,e]oxepine-8-carboxylate 、 propyl (Z)-11-cyanocyclopropylmethylene-6,11-dihydrodibenzo[b,e]oxepine-8-carboxylate 以in the same manner as in Reference Example B9, step 3, (E)-2-(2-hydroxymethyl-5,11-dihydrobenzooxepino[3,4-b]pyridin-5-ylidene)propiononitrile (0.191 g, 62%) was obtained的产率得到(E)-2-(2-hydroxymethyl-5,11-dihydrobenzooxepino[3,4-b]pyridin-5-ylidene)propiononitrile