Progress towards an intramolecular Diels–Alder ring-expansion approach to taxinine: the interplay of Lewis acids and high pressure
作者:Andrew J. Phillips、Jonathan C. Morris、Andrew D. Abell
DOI:10.1016/s0040-4039(00)00248-3
日期:2000.4
A concise route to a bicyclo[4.2.1] ring system, based on an intramolecular Diels-Alder reaction, has been developed. Preliminary results on the interplay between Lewis acids and high pressure to facilitate the reaction are described. Products with isomerized double bonds were obtained with 1 equivalent of Lewis acid at 0 degrees C. The stereochemistry of these compounds has been determined by X-ray crystallography. Double bond isomerization is suppressed by the use of excess Lewis acid at -78 degrees C or high pressure. (C) 2000 Elsevier Science Ltd. All rights reserved.