In a process for separating a mixture comprising cyclohexanone and phenol, at least a portion of the mixture is distilled in the presence of a solvent including at least two alcoholic hydroxyl groups attached to non-adjacent saturated carbon atoms and at least one hemiketal defined by the formula (I) or the formula (II):
wherein R
1
, the same or different at each occurrence, is independently an alkylene group having from 2 to 10 carbon atoms, R
2
is an alkylene group having from 4 to 10 carbon atoms, and R
3
is hydrogen or the following group:
and/or an enol-ether derived from the hemiketal defined by the formula (I) or the formula (II), wherein the total concentration of the hemiketal and the enol-ether, expressed in terms of weight percentage on the basis of the total weight of the feed to the distilling step (a), is at least 0.01%.
US4046801A
申请人:——
公开号:US4046801A
公开(公告)日:1977-09-06
US9181165B2
申请人:——
公开号:US9181165B2
公开(公告)日:2015-11-10
US9464020B2
申请人:——
公开号:US9464020B2
公开(公告)日:2016-10-11
Asymmetric Synthesis of Cyclic Hydroxy Ketones Derived from Enol Ethers via Sharpless Asymmetric Dihydroxylation. A Study in the Correlation of the Enol Ether Chain Length and Enantioselectivity
作者:Benjamin F. Marcune、Sandor Karady、Paul J. Reider、Ross A. Miller、Mirlinda Biba、Lisa DiMichele、Robert A. Reamer
DOI:10.1021/jo034854o
日期:2003.10.1
The Sharpless asymmetric dihydroxylation reaction of enolethers derived from their corresponding cyclic ketones, gave alpha-hydroxyketones with high enantioselectivity. The enantiomeric excess was found to be proportional to the length of the unbranched enolether chain with a maximum ee for the pentyl enolether. An efficient synthesis of alpha-hydroxy chromanone in >90% ee was demonstrated using