The stereocontrolled total synthesis of (−)-ephedradine A (1) has been accomplished. Construction of opticallyactive dihydrobenzofuran-ring was performed by a novel asymmetric C–H insertion reaction. After an intramolecular ester–amide exchange reaction and a Sharpless asymmetric aminohydroxylation reaction, construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular
An Efficient Synthesis of OpticallyActive<i>trans</i>-2-Aryl-2,3-dihydrobenzofuran-3-carboxylicAcid Esters via C-H Insertion Reaction
作者:Tohru Fukuyama、Wataru Kurosawa、Toshiyuki Kan
DOI:10.1055/s-2003-39316
日期:——
Optically active trans-2-Aryl-2,3-dihydrobenzofuran-3-carboxylic acid esters were synthesized by intramolecular C-H insertion reaction. Upon treatment with a catalytic amount of Rh2(R-DOSP)4, aryldiazoester 8c possessing a chiral auxiliary underwent C-H insertion reaction to give 9c in high yield and in high selectivity (84% yield, 86% de).