An efficient regioselective halogenation of 5-amino-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-ones
摘要:
An effective regioselective halogenation of 5-arnino-endo-tricyclo decenyl enaminones 6 using N-halosuccinimides is reported. The reaction is extremely fast and the yields are almost quantitative. Exclusive alpha,N-dihalo or alpha,gamma-dihalo compounds can be obtained by tuning the reaction conditions. Facile transfer of bromine from alpha,N-dibromo enaminones 8 has been observed, A rationale for the formation of the various halogenated products is presented. The alpha,gamma-dihalo enaminones allow further functionalisation of the tricyclodecadienone system and thus are promising precursors for pharmacologically interesting halo-cyclopentanoids. More importantly, the otherwise more reactive norbornene double bond remained intact under these halogenation conditions. (C) 2002 Elsevier Science Ltd. All rights reserved.
Asymmetric desymmetrization of pseudo-meso 5-hydroxy-endo-tricyclo[5.2.1.02,6]deca-4,8-dien-3-ones
作者:Namakkal G Ramesh、Frank J.A.D Bakkeren、Debby de Groot、Umberto Passamonti、Antonius J.H Klunder、Binne Zwanenburg
DOI:10.1016/s0040-4020(01)01007-9
日期:2001.12
-tricyclo[5.2.1.02,6]deca-4,8-dien-3-one. Desymmetrization using (S)-prolinol or its methyl ether leads to the corresponding enaminones in high yields and with a de of 50%. Complete separation of the diastereomers has been conveniently achieved via their acetates. The absolute stereochemistry of the major diastereomer was determined by single-crystal X-ray diffraction analysis. Reductive elimination