titanium(IV) isopropylate 、
(S)-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-1-(4-methoxyphenyl)azetidine-2,3-dione 、
3-Diazo-1,3-dihydro-1-methyl-5-nitro-2H-indol-2-one 在
dirhodium tetraacetate 作用下,
以
二氯甲烷 为溶剂,
反应 2.0h,
以89%的产率得到(3R)-3-[(2S,3S)-2-[(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]-3-hydroxy-1-(4-methoxyphenyl)-4-oxoazetidin-3-yl]-1-methyl-5-nitro-3-propan-2-yloxyindol-2-one