methyl 2-(2-pyridyl)-2-(2-carbomethoxymethoxyphenoxy)-acetate   、                                                                                      
2,2'-[(1,2-phenylene)bis(oxy)]bis[acetic acid] dimethyl ester                                                                                                                                                                                                                                                                                                          以there is obtained sequentially 2-(2-pyridyl)-3-oxo-4-carbomethoxy-3,4-dihydro-2H-1,5-benzodioxepin的产率得到2-(2-pyridyl)-3-oxo-4-carbomethoxy-3,4-dihydro-2H-1,5-benzodioxepin