[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
Quorum Sensing in Bacterial Species that Use Degenerate Autoinducers Can Be Tuned by Using Structurally Identical Non-native Ligands
作者:Andrew G. Palmer、Evan Streng、Kelsea A. Jewell、Helen E. Blackwell
DOI:10.1002/cbic.201000551
日期:2011.1.3
Talk this way: Different bacteria useidenticalquorumsensing (QS) signals to regulate important cell‐density dependent phenotypes. Herein, we show that non‐native compounds previously identified as QS modulators in one speciescan be reappropriated to regulate QS in alternate bacteria that utilize the same native signal. These results considerably broaden the species range of the known non‐native QS
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.