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