共 11 条
Aspects of the chemistry of 8-azabicyclo[3.2.1] octanes
被引:7
作者:
Baylis, Alison M.
[1
]
Thomas, Eric J.
[1
]
机构:
[1] Univ Manchester, Sch Chem, Manchester M13 9PL, Lancs, England
来源:
基金:
英国工程与自然科学研究理事会;
关键词:
alkaloids;
tropanones;
fragmentation reactions;
cyclisation reactions;
cyclopropanes;
D O I:
10.1016/j.tet.2007.08.109
中图分类号:
O62 [有机化学];
学科分类号:
070303 ;
081704 ;
摘要:
Mesylation and elimination from dimethyl 3-hydroxy-8-azabicyclo[3.2.1] octane-2,8-dicarboxylate gave a conjugated alkenyl ester. Reduction of the mesyloxy ester by di-isobutylaluminium hydride was also accompanied by elimination giving an unsaturated aldehyde. Treatment of the mesylate of the corresponding monoprotected diol with potassium tert-butoxide gave a 2-unsubstituted alkene via a Grob fragmentation but a different alkene was obtained using 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU) in acetonitrile. Epoxidation of both the protected hydroxy-alkene and the free hydroxy-alkene was stereoselective in favour of epoxidation from the exo-face, and ring-opening of the hydroxy-epoxide using hydrogen bromide gave the diaxial bromohydrin. Treatment of a 2-iodomethyl-3-oxo-8-azabicyclo[3.2.1] octane with tert-butyllithium gave a cyclopropane, whereas the corresponding iodo-alcohol gave the 1-azatricyclo[5.3.0.0(4,10)] decan-2-one as the major product. (c) 2007 Elsevier Ltd. All rights reserved.
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页码:11666 / 11671
页数:6
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