✦ LIBER ✦
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
✍ Scribed by Langschwager, Wolf ;Hoffmann, H. Martin R.
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 605 KB
- Volume
- 1995
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
tautomer I 4-Oxocarboxylic acids I Keto-cyclol tautomerism (2-Oxocyclohexyl)acetic acid 10 was converted into bicyclic alkoxy y-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 well-defined compound. The angular methyl group seems essential for the spontaneous lactonization. 5,5-Dialkoxy-4-oxocarboxylic acids 26a, b without a n angular methyl group did not cyclize to bicyclic hydroxy y-lactones. 0 7a ' 6 7b