N-苯基马来酰亚胺   、                                                                                      
2,5-diphenyl-1,3-dithiolylium-4-olate                                                                                                                                                                                              以
                                                                                         xylene                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 2,4,7-triphenyl-(3a
c,7a
c)-tetrahydro-4
r,7
c-episulfano-thiopyrano[3,4-
c]pyrrole-1,3,6-trione   、                                                                                             
2,4,7-triphenyl-(3at,7at)-tetrahydro-4r,7c-episulfano-thiopyrano[3,4-c]pyrrole-1,3,6-trione