. 2014 Nov 19;19(11):19050–19065. doi: 10.3390/molecules191119050
© 2014 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 license (http://creativecommons.org/licenses/by/4.0/).
Scheme 1.
Synthesis of compounds 5a–c and 6a–d.