. 2021 Jan 11;26(2):337. doi: 10.3390/molecules26020337
© 2021 by the authors.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Scheme 1.
Plausible production mechanism of 9–11 from 4.