Enantioselective Total Synthesis of (+)-Gliocladine C: Convergent Construction of Cyclotryptamine-Fused Polyoxopiperazines and a General Approach for Preparing Epidithiodioxopiperazines from Trioxopiperazine Precursors
作者:John E. DeLorbe、Salman Y. Jabri、Steven M. Mennen、Larry E. Overman、Fang-Li Zhang
DOI:10.1021/ja201789v
日期:2011.5.4
A concise second-generation total synthesis of the fungal-derived alkaloid (+)-gliocladin C (11) in 10 steps and 1196 overall yield from isatin is reported. In addition, the epipolythiodioxopiperazine (ETP) natural product (+)-gliocladine C (6) has been prepared in six steps and 2996 yield from the di-(tert-butoxycarbonyl) precursor of 11. The total synthesis of 6 constitutes the first total synthesis of an ETP natural product containing a hydroxyl substituent adjacent to a quaternary carbon stereocenter in the pyrrolidine ring.
Enantioselective Organocatalytic Addition of Nitroalkanes to Oxindolylideneindolenines for the Construction of Chiral 3,3-Disubstituted Oxindoles
作者:Jian-Zhou Huang、Xiang Wu、Liu-Zhu Gong
DOI:10.1002/adsc.201300373
日期:2013.9.16
An enantioselectiveorganocatalyticaddition of nitroalkanes to oxindolylideneindolenines in the presence of bifunctional organocatalysts has been established to provide an efficient entry to 3,3‐disubstituted oxindole derivatives in high yields and with excellent enantioselectivities. The transformation has been applied to the preparation of the key intermediate for a formal total synthesis of (+)‐gliocladin