DL-camphorquinone   、                                                                                      
N1-{(1S,2R,3S,4R)-1,7,7-trimethyl-4'-methylenedihydro-3'H-spiro[bicyclo[2.2.1]heptane-2,2'-furan]-3-yl}benzene-1,2-diamine                                                                                                                                                              在
                                                                                                                                                                                 
对甲苯磺酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 4.0h,
                                                                                                                以31%的产率得到N1-[(1S,3E,4R)-2-oxo-1,7,7-trimethylbicyclo[2.2.1]hept-3-ylidene]-N2-{(1S,2R,3S,4R)-1,7,7-trimethyl-4'-methylenedihydro-3'H-spiro[bicyclo[2.2.1]heptane-2,2'-furan]-3-yl}benzene-1,2-diamine