CHLORINATION OF ALPHA,BETA-UNSATURATED KETONES AND ESTERS IN THE PRESENCE OF ACID SCAVENGERS

被引：9

作者：

HEASLEY, VL ^{[1
]}

ELLIOTT, SL ^{[1
]}

ERDMAN, PE ^{[1
]}

FIGUEROA, DE ^{[1
]}

KROSLEY, KW ^{[1
]}

LOUIE, TJ ^{[1
]}

MOORE, HB ^{[1
]}

MUDGE, BP ^{[1
]}

NOGALES, DF ^{[1
]}

NORDEEN, J ^{[1
]}

OAKES, ML ^{[1
]}

ROSBRUGH, JW ^{[1
]}

SAUERBREY, AM ^{[1
]}

SHIBUYA, TY ^{[1
]}

STANLEY, MS ^{[1
]}

STEWART, CC ^{[1
]}

SHELLHAMER, DF ^{[1
]}

HEASLEY, GE ^{[1
]}

机构：

[1] SO NAZARENE UNIV,DEPT CHEM,BETHANY,OK 73008

来源：

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2 | 1991年 / 03期

关键词：

D O I：

10.1039/p29910000393

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The chlorination of a series of alpha,beta-unsaturated ketones and esters by Cl2 in CH3OH, with and without acid scavengers such as N-chlorosuccinimide (NCS), pyridine and 2,6-lutidine, is described. Methyl vinyl ketone and cyclohex-2-enone have also been chlorinated in ethanol. Mixtures of Markovinikov(M) and anti-Markovnikov(AM) methoxy chlorides and dichlorides are formed in most cases; phenyl vinyl ketone gives no M products in the absence of pyridine, M methoxy chloride is not formed with (E)-4-chlorobut-3-en-2-one under any conditions, pyridine has no effect on the product ratios and methyl 3-chlorobut-2-enoate forms only dichloride. Chlorination of the ketones in the presence of the pyridines results in a significant increase in the M regioisomer (except for methyl isopropenyl ketone and the ketones mentioned), giving M:AM ratios which are similar to the corresponding esters. Ratios for the esters are not affected significantly by pyridine. We ascribe the effect of the pyridine bases to the elimination of acid and the acid-catalysed mechanism, permitting the chlorination to occur via a carbon-carbon pi-bond (chloronium ion) mechanism. The rate of chlorination of methyl vinyl ketone is retarded by pyridine but is still considerably faster than methyl acrylate. NCS, in contrast to N-bromosuccinimide (NBS) reported previously, has no effect on the M:AM ratio. The chlorination of methyl vinyl ketone with NCS and HCl gives markedly different results from Cl2.

引用

页码：393 / 399

页数：7

共 10 条

[1]

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