These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
A variation of Favorskii rearrangement mechanism under weakly acidic conditions_the case of clobetasol propionate degradation in solution.pdf (813.35 kB)

A Variation of Favorskii Rearrangement Mechanism Under Weakly Acidic Conditions: The Case of Clobetasol Propionate Degradation in Solution

submitted on 05.02.2020, 18:05 and posted on 06.02.2020, 11:12 by Yun Tian, Haoran Zhang, Zach Zhu, Li Chen, Evelyn Wang, Jianyang Jin, Dan Li, Wenquan Zhu, Min Li, Lei Fu
This paper describes our efforts in proposing a novel mechanism for the formation of the major degradant of clobetasol propionate under weakly acidic conditions through a comprehensive investigation. In the proposed mechanism, the key Favorskii intermediate plays a critical role. This variation of the original Favorskii rearrangement, which proceeds only under alkaline conditions, has not been reported before. This mechanism enriches the understanding of the degradation chemistry of corticosteroids containing the α-haloketone moiety on their 17-position.


Email Address of Submitting Author


Huahai Pharmaceutical Co., Ltd and Huahai US Inc.



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest.

Version Notes

This is the first version.