+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Ozonolysis of 1,4-cyclohexadienes in the presence of methanol and acid. Mechanism and intermediates in the conversion of 1,4-cyclohexadiene derivatives to beta-keto esters

Ozonolysis of 1,4-cyclohexadienes in the presence of methanol and acid. Mechanism and intermediates in the conversion of 1,4-cyclohexadiene derivatives to beta-keto esters

Journal of Organic Chemistry 69(12): 4135-4139

Conditions for the preparation of beta-keto esters directly from 1,4-cyclohexadiene derivatives are described. This procedure is a further step in the application of the synthetic methodology, which consists of the combination of Birch reduction of available benzene derivatives followed by ozonolysis. In this work, the syntheses of derivatives of dimethyl gamma-keto-alpha-aminoadipate and dimethyl beta-keto glutamate from the corresponding 1,4-cyclohexadiene derivatives are described. The latter compounds are prepared from phenylalanine and phenylglycine, respectively. The study of the ozonolysis of simple alkyl derivatives of 1,4-cyclohexadiene in the presence of methanol, both in the presence and absence of acid, helped to establish the mechanism of this reaction. The proximity of the two double bonds, which are cleaved, leads to the intermediate formation of 1,2-dioxolane derivatives that could be identified by NMR spectroscopy. It is shown that regardless of the regioselectivity of the cleavage of the primary ozonide, which is formed, all 1,2-dioxolane derivatives can lead to beta-keto esters. This is due to the equilibrium between these dioxolanes in the presence of methanol and acid.

(PDF emailed within 0-6 h: $19.90)

Accession: 049839724

Download citation: RISBibTeXText

PMID: 15176839

DOI: 10.1021/jo049731y

Related references

Ozonolysis of olefins iv. ozonolysis of polyunsaturated fatty esters in hydrochloric acid methanol. Chemistry and Physics of Lipids 55(1): 67-72, 1990

Reactions of N-hydroxysuccinimide esters of anthranilic acids with anions of beta-keto esters. A new route to 4-oxo-3-quinolinecarboxylic acid derivatives. Chemical & Pharmaceutical Bulletin 48(2): 211-214, 2000

Enantiomerically pure n boc protected beta keto gamma amino acid esters from simple keto precursors a novel stereocontrolled approach to statine derivatives with any desired configuration. Synlett (5): 253-255, 1990

Direct trifluoromethylation of alpha keto esters to beta beta beta trifluorolactic acid derivatives using trifluoromethyltrimethylsilane. Synlett (9): 643-644, 1991

Reversed Stereochemical Control in the Presence of CeCl(3) and TiCl(4) in the Lewis Acid Mediated Reduction of alpha-Alkyl-beta-keto Esters by Metal Hydrides. A General Methodology for the Diastereoselective Synthesis of syn- and anti-alpha-Alkyl-beta-hydroxy Esters. Journal of Organic Chemistry 64(6): 1986-1992, 2001

In vitro reactions of alkaloids 2. selective decarbalkoxylation of geminal di esters beta keto esters and delta keto beta gamma unsaturated esters. Journal of Organic Chemistry 46(26): 5376-5379, 1981

Ketoester reductase for conversion of keto acid esters to optically active hydroxy acid esters. Official Gazette of the United States Patent & Trademark Office Patents 1187(1): 383, June 4, 1996

Synthesis of 3 beta 14 dihydroxy 5 beta 14 beta pregnan 20 one c 3 derivatives ozonolysis of digitoxin and digitoxigenin and their derivatives followed by zinc acetic acid reduction to the c 21 methyl ketone. Journal of the Chemical Society Perkin Transactions I (4): 823-830, 1991

Keto-enol-tautomerism in heterocyclic beta-ketocarboxylic acid esters. 3. Configuration and conformation of 2,6-dialkyl substituted beta-ketodicarboxylic acid esters. Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft 302(2): 147-151, 1969

Ultrasound assisted production of fatty acid methyl esters from transesterification of triglycerides with methanol in the presence of KOH catalyst: optimization, mechanism and kinetics. Ultrasonics Sonochemistry 21(2): 467-471, 2014

Construction of medium and large sized cyclic beta keto esters or nitriles via one pot three carbon ring expansion of carbocyclic beta keto esters and its application to the synthesis of levo muscone. Journal of Organic Chemistry 55(3): 820-826, 1990

Keto-enol tautomerism in heterocyclic beta-ketocarboxylic acid esters. 4. Nuclear resonance spectroscopic studies on enolized piperidone dicarboxylic acid esters. Die Pharmazie 25(5): 319-322, 1970

Mechanism of amination of β-keto esters by azadicarboxylates catalyzed by an axially chiral guanidine: acyclic keto esters react through an E enolate. Journal of the American Chemical Society 134(40): 16869-16876, 2012

Catalytic asymmetric synthesis of alpha,beta-epoxy esters, aldehydes, amides, and gamma,delta-epoxy beta-keto esters: unique reactivity of alpha,beta-unsaturated carboxylic acid imidazolides. Journal of the American Chemical Society 123(38): 9474-9475, 2001

Methods for preparation of hetero bi functional nitroxides alpha beta unsaturated ketones beta keto esters cyano nitro derivatives. Canadian Journal of Chemistry 60(12): 1432-1438, 1982