Pyrroles and related compounds. Part XXVI. Pyrrole β-keto-esters

Autor:	T. Trefor Howarth, Jean Judge, George W. Kenner, Anthony H. Jackson, David J. Newman
Rok vydání:	1974
Předmět:	Chemistry Malonic acid Chloride Sodium salt Acylation chemistry.chemical_compound Carboxylation Hydrogenolysis medicine Trifluoroacetic acid Organic chemistry lipids (amino acids peptides and proteins) medicine.drug Pyrrole
Zdroj:	J. Chem. Soc., Perkin Trans. 1. :490-501
ISSN:	1364-5463 0300-922X
DOI:	10.1039/p19740000490
Popis:	Various attempts to synthesise β-keto-esters of pyrroles for use as model compounds, or as intermediates in chlorophyll synthesis, are described. Carboxylation of acetylpyrroles, using dialkyl carbonates or chloroformates, gave a variety of products, including a β-keto-ester and (unexpectedly)N-alkyl- as well as N-alkoxycarbonyl-pyrroles. Attempts to utilise pyrrylacetylenes were unsuccessful, as were direct acylation reactions with derivatives of malonic ester. The most successful approach involved the coupling of a pyrryl acid chloride with the sodium salts of monoalkyl monobenzyl (or mono-t-butyl) esters of malonic acid; the β-keto-diester thus obtained could then be converted (by hydrogenolysis or treatment with cold trifluoroacetic acid) into the desired β-keto-ester.
Databáze:	OpenAIRE
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