. 2020 Dec 1;25(23):5667. doi: 10.3390/molecules25235667
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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 4.
Our planned route to key intermediate 17a.