Donohoe Timothy J, Thomas Rhian E, Cheeseman Matthew D, Rigby Caroline L, Bhalay Gurdip, Linney Ian D
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, United Kingdom.
Org Lett. 2008 Aug 21;10(16):3615-8. doi: 10.1021/ol801415d. Epub 2008 Jul 18.
A general strategy for the production of pyrrolizidine alkaloids is described, starting from intermediate (+)-9. The key features are diastereoselective dihydroxylation, inversion at the ring junction by hydroboration of an enamine, and ring closure to form the bicyclo ring system. This route is attractive because of its brevity and versatility; four natural products were prepared with differing stereochemistry and substitution patterns. Finally, this work allowed assignment of the absolute stereochemistry of 2,3,7-triepiaustraline and hyacinthacine A 7.
本文描述了一种从中间体(+)-9出发生产吡咯里西啶生物碱的通用策略。关键步骤包括非对映选择性二羟基化、通过烯胺硼氢化反应在环连接处进行构型翻转以及闭环形成双环体系。这条路线因其简洁性和通用性而具有吸引力；制备了四种具有不同立体化学和取代模式的天然产物。最后，这项工作确定了2,3,7-三表澳洲千里光碱和天蓝星碱A 7的绝对立体化学结构。
