Highly diastereoselective synthesis of orthoquinone monoketals through λ13-iodane-mediated oxidative dearomatization of phenols
Résumé
(Chemical Equation Presented) Versatile chiral substrates for asymmetric synthesis are formed through the spiroketalization of phenols with a chiral substituted ethanol unit O-tethered to the ortho position upon treatment with PhI-(OAc)2 (see example; TFE = 2,2,2-tri-fluoroethanol). Intermediates with a six-membered iodine(III)-containing ring (the natural localized molecular orbitals associated with the I-C6 bond are shown) undergo ligand coupling to give the spiroketals. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.