The dimerisation and competitive cycloaddition of 2-methoxycarbonylbuta-1,3-diene with electron-rich dienes has been investigated. Experimental results provide evidence that the enthalpy of the π-system significantly influences the energy of the transition state of cycloadditions of this type. This has been corroborated by ab initio calculations. We propose an early reorganisation of the π-electrons in such cycloadditions to explain the influence stated above.
[EN] CONTINUOUS DEHYDROGENATION OF 1,4-CARBOXYLATE SUBSTITUTED CYCLOHEXENES<br/>[FR] DÉSHYDROGÉNATION EN CONTINU DE CYCLOHEXÈNES SUBSTITUÉS PAR 1,4-CARBOXYLATE
申请人:AMYRIS INC
公开号:WO2012082725A1
公开(公告)日:2012-06-21
A method which comprises contacting the cyclohexene ring containing compounds having carboxylate derivatives at the 1 and 4, and optionally the 2, positions with one or more dehydrogeoation catalysts, optionally in the presence of one or more oxidants, in a continuous flow mode under conditions such that compounds containing an aromatic ring with carboxylate derivatives at the 1. and 4 positions, and optionally the 2 position, are prepared. The invention also relates to such compounds derived from starting materials derived from renewable resources.
PREPARATION OF TRANS,TRANS MUCONIC ACID AND TRANS,TRANS MUCONATES
申请人:Frost John W.
公开号:US20100314243A1
公开(公告)日:2010-12-16
The present invention relates to the isomerization of cis,cis and/or cis,trans muconic acid or esters thereof to trans,trans muconic acid or esters thereof and to the esterification of such muconic acids.
cis,cis-Muconic acid isomerization and catalytic conversion to biobased cyclic-C<sub>6</sub>-1,4-diacid monomers
作者:Jack M. Carraher、Toni Pfennig、Radhika G. Rao、Brent H. Shanks、Jean-Philippe Tessonnier
DOI:10.1039/c7gc00658f
日期:——
selective formation of trans,trans-muconic acid. We demonstrate that the reactivity of muconic acid in aqueous media strongly depends on pH. Under alkaline conditions, cis,cis-muconic acid is deprotonated to the corresponding muconate dianion. This species is stable for extended periods of time and does not isomerize. Conversely, cis,cis-muconic acid readily isomerizes to its cis,trans-isomer under acidic
A method for cycloaddition of dimethyl muconate is disclosed. According to the method, a direct transferring of a solid phase trans,trans-dimehtyl muconate into a reactor pre-filled with ethylene gas increases the efficiency of the reaction and suppress side reactions resulting an improvements in yield and purity. Furthermore, the method is capable of obtaining a high yield of dimethylcyclohex-2-en-1,4-dicarboxylate at a lower cost, and therefore is also useful for the mass synthesis of dimethyl terephthalate.