Synthesis of chromane compounds and their derivatives by a copper-catalyzed conjugate addition reaction

摘要

The present invention relates to the preparation of chromane compounds and their derivatives by a copper-catalyzed conjugate addition reaction. It has been observed that in highly stereoselective manner a methyl group can be introduced to the 2 position of chromane ring by reaction of a chromenone with Al(CH₃)₃ in the presence of a Cu(I) salt and specific chiral phosphoramidites. The compounds obtained are important intermediates particularly for the synthesis of chiral tocopherols.