. 2017 May 19;56(25):7227–7232. doi: 10.1002/anie.201703155
© 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Scheme 5.
Possible stereochemical models.