Studies on the terpenoids and related alicyclic compounds XXXIX. A synthesis of .ALPHA.-methylene-.GAMMA.-lactones fused to medium and large rings by intramolecular cyclization of formylated allyl halides

Autor:	Koji Yamakawa, Kiyoshi Nishitani, Masashi Isozaki
Rok vydání:	1990
Předmět:	chemistry.chemical_classification Bicyclic molecule Intramolecular reaction Chemistry Stereochemistry Halide General Chemistry General Medicine Ring (chemistry) Medicinal chemistry chemistry.chemical_compound Intramolecular force Reagent Drug Discovery Methylene Lactone
Zdroj:	Chemical and Pharmaceutical Bulletin. 38:28-35
ISSN:	1347-5223 0009-2363
DOI:	10.1248/cpb.38.28
Popis:	Carbocyclic rings fused to an α-methylene-γ-lactone unit were synthesized from ω-formylated β-ethoxycarbonylallyl halides (4a-g) through intramolecular cyclization by the use of a low-valent chromium reagent, prepared from CrCl3 and LiAlH4, in N, N-dimethylformamide. α-Methylene-γ-lactones fused to medium (eight-membered) or large (twelve-and fourteen-membered) ring system (5a, c and d) were synthesized by this method in good to fairly good yields. However, the formylated allyl halide (4b), expected to afford a ten-membered carbocyclic ring system, gave dilactones fused to a twenty-membered ring unit even under a high dilution reaction condition.
Databáze:	OpenAIRE
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