由于环、立体中心和氧合的独特融合,克莱罗丹二萜家族具有一系列令人印象深刻的生物活性和高合成挑战。在这里,我们公开了三个成员,scaparvins B、C 和 D 的第一次全合成,通过几个化学选择性和精心策划的步骤推动的路线。一种这样的操作是在最小化烯烃环氧化的条件下通过叔CH键的氧化将羧酸转化为内酯的定制后期CH官能化。这一步提供了完成目标的关键功能。此外,使用适当的手性催化剂与拉瓦尔二烯使序列具有对映选择性。
Constructing the architecturally distinctive ABD-tricycle of phomactin A through an intramolecular oxa-[3+3] annulation strategy
作者:Grant S. Buchanan、Kevin P. Cole、Gang Li、Yu Tang、Ling-Feng You、Richard P. Hsung
DOI:10.1016/j.tet.2011.09.111
日期:2011.12
Our efforts in constructing the ABD-ring of phomactin A through an intramolecular oxa-[3+3] annulation strategy is described. This struggle entailed finding a practical and efficient preparation of annulation precursor, and a realization of the unexpected competing regioisomeric pathway. The success entailed accessing the A-ring through Diels Alder cycloaddition of Rawal's diene. Furthermore, the discovery that the regioisomers from the annulation existed as atropisomers with respect to the D-ring olefin and that they could be equilibrated to the desired ABD-tricycle, allowing large quantities of tricycle to be accessed. Published by Elsevier Ltd.