[EN] SYNTHESIS OF CHROMANE COMPOUNDS AND THEIR DERIVATIVES BY A COPPER-CATALYZED CONJUGATE ADDITION REACTION<br/>[FR] SYNTHÈSE DE COMPOSÉS DE CHROMANE ET DE LEURS DÉRIVÉS PAR UNE RÉACTION D'ADDITION CONJUGUÉE CATALYSÉE PAR DU CUIVRE
申请人:DSM IP ASSETS BV
公开号:WO2015059129A1
公开(公告)日:2015-04-30
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.
Total Synthesis of (<i>R</i>,<i>R</i>,<i>R</i>)-α-Tocopherol Through Asymmetric Cu-Catalyzed 1,4-Addition
作者:Andreas Ole Termath、Hanna Sebode、Waldemar Schlundt、René T. Stemmler、Thomas Netscher、Werner Bonrath、Hans-Günther Schmalz
DOI:10.1002/chem.201404379
日期:2014.9.15
introducing a disposable activating substituent at C‐3, the asymmetric 1,4‐addition to a notoriously unreactive 2‐substituted chromenone was achieved with high levels of (2R)‐stereoselectivity in the presence of a chiral CuI‐phosphoramidite complex as a catalyst. This paved the way for an efficient and conceptually novel synthesis of (R,R,R)‐α‐tocopherol from readily available starting materials.
Total Synthesis of (2<i>RS</i>)-α-Tocopherol through Ni-Catalyzed 1,4-Addition to a Chromenone Intermediate
作者:Andreas Ole Termath、Janna Velder、René T. Stemmler、Thomas Netscher、Werner Bonrath、Hans-Günther Schmalz
DOI:10.1002/ejoc.201402240
日期:2014.6
A novel strategy for the total synthesis of α-tocopherol (“vitamin E”) was elaborated on the basis of the conjugate addition of AlMe3 (as a methyl anion equivalent) to a 2-substituted chromenone. Starting from trimethylhydroquinone and (R,R)-hexahydrofarnesol, the required chromenone substrate was efficiently prepared in a short sequence exploiting a TiCl4-mediated Fries rearrangement and a KOtBu-induced
3,4-Dihydro-2,5,7,8-tetramethyl-2H-1-benzopyranderivate und Verfahren zu ihrer Herstellung
申请人:F. HOFFMANN-LA ROCHE & CO.
Aktiengesellschaft
公开号:EP0235510A2
公开(公告)日:1987-09-09
Die Erfindung bezieht sich auf neue 2-Halochromane und ihre Kupplung an verschiedene Nukleophile, wobei Vitamin E oder neue Zwischenprodukte für Vitamin E entstehen.