7494-85-1Relevant articles and documents
Ring-Chain Tautomerism Provides a Route to 7a-Hydroxy-3a-methyl-2,7-dioxoperhydrobenzofuran. Synthesis of the Hydroxy γ-Lactone Substructure of Myrocin and Other Bioactive Natural Products
Langschwager, Wolf,Hoffmann, H. Martin R.
, p. 797 - 802 (2007/10/02)
(2-Oxocyclohexyl)acetic acid 10 was converted into bicyclic alkoxy γ-lactones 12a-d via intermediate chloro lactone 11 and alkanolysis.Similarly, lactones 15a,b and 18 were prepared.In contrast, simple ring-chain tautomerism directly afforded the title heterocycle 28, a crystalline, stable and welldefined compound.The angular methyl group seems essential for the spontaneous lactonization. 5,5-Dialkoxy-4-oxocarboxylic acids 26a, b without an angular methyl group did not cyclize to bicyclic hydroxy γ-lactones. - Key Words: Hydroxy lactone, 5-membered, (lactol) tautomer / 4-Oxocarboxylic acids / Keto-cyclol tautomerism.