examined establishing an efficient method for the preparation of alkyl(1,3-butadien-2-yl)methanols. Application of this method to chiral acetals prepared from (R,R)-2,4-pentanediol led to chiral alkyl(1,3-butadien-2-yl)methanol derivatives with high optical purity which were alternatively synthesized by the Sharpless kinetic resolution of racemic alkyl(1,3-butadien-2-yl)methanols.
[EN] PROCESS OF ASYMMETRIC HYDROGENATION OF KETALS AND ACETALS<br/>[FR] PROCÉDÉ D'HYDROGÉNATION ASYMÉTRIQUE DE CÉTALS ET D'ACÉTALS
申请人:DSM IP ASSETS BV
公开号:WO2014096096A1
公开(公告)日:2014-06-26
The present invention relates to a process of the asymmetric hydrogenation of a ketal of an unsaturated ketone or an acetal of an unsaturated aldehyde by molecular hydrogen in the presence of at least one chiral iridium complex. This process yields chiral compounds in a very efficient way and is very advantageous in that the amount of iridium complex can be remarkably reduced.
[EN] USING MIXTURES OF E/Z ISOMERS TO OBTAIN QUANTITATIVELY SPECIFIC PRODUCTS BY COMBINING ASYMMETRIC HYDROGENATION AND ISOMERIZATION<br/>[FR] UTILISATION DE MÉLANGES D'ISOMÈRES E/Z EN VUE D'OBTENIR DES PRODUITS SPÉCIFIQUES DE MANIÈRE QUANTITATIVE PAR COMBINAISON D'HYDROGÉNATION ASYMÉTRIQUE ET D'ISOMÉRISATION
申请人:DSM IP ASSETS BV
公开号:WO2014096107A1
公开(公告)日:2014-06-26
The present invention relates to a process of manufacturing compound having stereogenic centres from a mixture of E/Z isomers of unsaturated compounds having prochiral double bonds. The hydrogenation product has a specific desired configuration at the stereogenic centres. The process involves an asymmetric hydrogenation and an isomerization step. The process is very advantageous in that it forms the desired chiral product from a mixture of stereoisomers of the starting product in an efficient way.
Intermediates for use in the preparation of vitamin E
申请人:AVENTIS ANIMAL NUTRITION S.A.
公开号:EP1179531A1
公开(公告)日:2002-02-13
Novel intermediate compounds which can be used in the preparation of phytone and Vitamin E and a process for the preparation thereof. A process for the preparation of phytone and Vitamin E from these compounds is also claimed.
Continuous flow Reductive Alkylation of Methanol by Aldehydes. Synthesis of O-Methyl Ethers and 1,1-Dimethoxyacetals
作者:Robbie Radjagobalou、Virgile Rouffeteau、Alexia Deleu、Pierre Nabokoff、Janine Cossy、Christophe Len
DOI:10.1016/j.mcat.2022.112321
日期:2022.5
A mild and efficient continuous-flow catalytic reductive alkylation of methanol by various linear and branched aliphatic aldehydes, at 140°C, using a Pd/C cartridge (1 wt% - 5 wt%) under 1 bar of hydrogen, has been developed to produce O-methyl ethers in high yields, and tolyl derivatives from aryl aldehydes. When the pourcentage of Pd/C was lower than 1 wt%, 1,1-dimethoxyacetals were obtained from