Toluene Dioxygenase-Mediated <i>cis</i>-Dihydroxylation of Aromatics in Enantioselective Synthesis. Asymmetric Total Syntheses of Pancratistatin and 7-Deoxypancratistatin, Promising Antitumor Agents<sup>1</sup>
作者:Tomas Hudlicky、Xinrong Tian、Kurt Königsberger、Rakesh Maurya、Jacques Rouden、Boreas Fan
DOI:10.1021/ja960596j
日期:1996.1.1
(1S,2S)-3-bromocyclohexa-3,5-diene-1,2-diol (9a), which is protected as the acetonide and converted to vinylaziridines 7, 15a, 63, and 64. Our route to (+)-pancratistatin features the coupling of a higherorder cyanocuprate (derived by ortho-metalation from N,N-dimethyl-2-[(tert-butyldimethylsilyl)oxy]-3,4-(methylenedioxy)benzamide) with aziridine 7 to generate 28, which contains the carbon framework
sulfur) is shown to be strongly dependent on the aryl substituent. By contrast, the analogous reaction of optically pure compounds 6 with 3-nitro-1,2,4-triazole led to racemic arenesulfonimidoyl nitrotriazoles 9. Opticallyactivecompounds of this type, (S)-9f (ee 99%) and (R)-9f (ee 92%). were obtained by semi-preparative chiral HPLC. The opticallyactive arenesulfonimidoyl imidazolium salt (R S,R C-)-8j