Enantioselective formal synthesis of (−)-ovalicin using quinic acid as a chiral template
作者:Achille Barco、Simonetta Benetti、Carmela De Risi、Paolo Marchetti、Gian P. Pollini、Vinicio Zanirato
DOI:10.1016/s0957-4166(98)00284-5
日期:1998.8
the synthesis of (−)-ovalicin was synthesized using (−)-quinicacid as the chiral source, through a series of stereocontrolled and efficient chemical reactions, thus establishing a new, formal synthesis of the natural target. The featuring spirocyclic epoxide function has been installed by internal Williamson ether synthesis using the functionalities originally present at C-1 of (−)-quinicacid after
Two chiral cyclohexanes 4 and 6, which are key intermediates for the total synthesis of ovalicin 1 and fumagillin 2, respectively, were synthesized from (2R,3S) 1,2-epoxy-4-penten-3-ol. The key steps involve an efficient construction of divinylalcohol 7 using methallyl Grignard reagent 9c, and an intramolecular olefin metathesis of 7. (C) 2011 Elsevier Ltd. All rights reserved.