New Cyclodimerization Reaction of (3,5-Di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic Acid

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Title:New Cyclodimerization Reaction of (3,5-Di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic Acid
Creators:
Nesvadba, Peter
Rzadek, Piotr
Rist, Günther
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 66, 8, pp. 1250-1256
Uncontrolled Keywords:Esterification, Quinone methides, Butyrolactones, Diaryl acetates, Reaction mechanism, Glyoxylic acid, Cyclodimerization

Abstract

(3,5-Di-<i>tert</i>-butyl-4-oxocyclohexa-2,5-dienylidene)acetic acid <strong>1a</strong> underwent on heating a new cyclodimerization reaction affording a 1 : 1 mixture of the racemic <i>cis</i>- and <i>trans</i>-isomeric lactone-acids <strong>2</strong>. The decisive structure elucidation of <strong>2</strong> was carried out after its mild esterification with diazomethane and separation of the racemic isomeric methyl esters <strong>3a</strong> and <strong>3b</strong>. The attempted esterification of <strong>2</strong> with methanol and sulfuric acid gave only the methyl diarylacetate <strong>4</strong>. In contrast to <strong>1a</strong>, which contains the carboxylic acid functionality no cyclodimerization was observed with the corresponding methyl ester <strong>1b</strong> or nitrile <strong>1c</strong>. <p>

Title:New Cyclodimerization Reaction of (3,5-Di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic Acid
Creators:
Nesvadba, Peter
Rzadek, Piotr
Rist, Günther
Uncontrolled Keywords:Esterification, Quinone methides, Butyrolactones, Diaryl acetates, Reaction mechanism, Glyoxylic acid, Cyclodimerization
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:66
Number:8
Page Range:pp. 1250-1256
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20011250UNSPECIFIED
ID Code:1854
Item Type:Article
Deposited On:06 Feb 2009 17:13
Last Modified:06 Feb 2009 16:13

Citation

Nesvadba, Peter; Rzadek, Piotr; Rist, Günther (2001) New Cyclodimerization Reaction of (3,5-Di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)acetic Acid. Collection of Czechoslovak Chemical Communications, 66 (8). pp. 1250-1256. ISSN 0010-0765

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