The High Stereoselectivity of the Tandem Sequence Diels-Alder Reaction/Ireland-Claisen Rearrangement Starting from Substituted O-(E)-Buta-1,3-dienyl Ketene Acetals and Cyclic Dienophiles
The stereoselective synthesis of dienyl esters with high atom- and step-economy has been largely unexplored. Herein, we report an efficient approach for the synthesis of E-dienyl esters via rhodium catalysis using carboxylic acid and acetylene as C2 synthon through the cascade of cyclometalation and C–O coupling. This protocol features mild conditions, excellent functional group tolerance, and exclusive
PROCESS FOR PRODUCING HYDROGENATED ESTER, HYDROGENATION CATALYST FOR USE THEREIN, AND PROCESS FOR PRODUCING THE CATALYST
申请人:Showa Denko Kabushiki Kaisha
公开号:EP1174414A1
公开(公告)日:2002-01-23
A process for producing a hydrogenated ester by hydrogenating an unsaturated group-containing ester having a specific structure by using a hydrogenating catalyst so as to obtain a hydrogenated ester with a high selectivity. It is preferred that the unsaturated group-containing ester as the raw material is diluted with an inert solvent and/or the concentration of carboxylic acid contained in the raw material is made 1 wt.% or less so as to effect a hydrogenation reaction. The hydrogenating catalyst to be used for the above hydrogenation may preferably be one comprising at least one metal selected from Group VIII elements, Group IX elements, and Group X elements in the periodic table, and preferably has an acidity of 1.0 × 10-1 mmol/g or less.