1-benzyl-2-crotonoyl-5,5-dimethyl-3-pyrazolidinone   、                                                                                      
1-benzylidene-3-oxo-1-pyrazolidinium-2-ide                                                                                                                                                              在
                                                                                                                                                                                 
(3aR,3a'R,8aS,8a'S)-2,2'-(cyclopropane-1,1-diyl)bis(3a,8a-dihydro-8H-indeno[1,2-d]oxazole)   、                                                                                                  copper(II) bis(trifluoromethanesulfonate)                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 0.5h,
                                                                                                                生成                                                 (5R,6S,7S)-6-(1-benzyl-5,5-dimethyl-3-oxopyrazolidine-2-carbonyl)-7-methyl-5-phenyl-tetrahydropyrazolo[1,2-a]pyrazol-1(5H)-one   、                                                                                             
(5S,6R,7R)-6-(1-benzyl-5,5-dimethyl-3-oxopyrazolidine-2-carbonyl)-7-methyl-5-phenyl-tetrahydropyrazolo[1,2-a]pyrazol-1(5H)-one