(2R,3S,4R,4'R,5S)-6,8-diaza-3,4-di-tert-butyldimethylsilyloxy-2-(2',2'-dimethyl-1',3'-dioxolane-4'-yl)-1-oxa-8-N-phenyl-spiro<4.4>nonane-7,9-dione 在
camphor-10-sulfonic acid 、
三氟乙酸 作用下,
以
1,4-二氧六环 为溶剂,
反应 24.5h,
生成 (2S,3R,4R,4'R,5S)-6,8-diaza-3,4-dihydroxy-2-(2',2'-dimethyl-1',3'-dioxolane-4'-yl)-1-oxa-8-N-phenyl-spiro[4.4]nonane-7,9-dione