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Updated: Apr 15, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Open-close: an alternative strategy to α-functionalization of lactone via enamine catalysis in one pot under mild
Yan-Kai Liu1, Zhi-Long Li2, Ji-Yao Li1
1†Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, P. R. China.
Abstract:
An open-close strategy in asymmetric catalysis is newly developed. With this powerful strategy, lactols are directly applied as potential precursors of lactones in enamine-based asymmetric Michael reactions providing a facile access to α-functionalized lactones containing two adjacent stereogenic centers as a single diastereomer in good to excellent yields (up to 99%) and with excellent enantioselectivities (most cases >99%). Moreover, the reaction products are shown to give highly functionalized derivatives by stepwise systematic transformations.
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