Conversion of unsaturated alcohols into functionalized tetrahydrofurans and tetrahydropyrans via nitrile oxide dipolar cycloadditions

Journal Article · Fri Oct 27 04:00:00 EDT 1989 · Journal of Organic Chemistry; (USA)

DOI:https://doi.org/10.1021/jo00283a021· OSTI ID:7071638

Hassner, A; Murthy, K S.K. ^[1]; Padwa, A; Dean, D C; Schoffstall, A M ^[2]; Chiacchio, U ^[3]

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1. Bar-Ilan Univ., Ramat-Gan (Israel)
2. Emory Univ., Atlanta, GA (USA)
3. Universita di Catania (Italy)

The intramolecular nitrile oxide cycloaddition (INOC) of a series of unsaturated oximino ethers has been investigated. The synthesis of the olefinic nitrile oxides involves treating an unsaturated alcohol with a {alpha}-bromoalkanal O-(trimethylsilyl)oxime in the presence of fluoride ion followed by subsequent sodium hypochlorite oxidation. The nitrile oxides were not isolated but spontaneously underwent intramolecular cycloaddition to give fused five- and six-membered ring ethers. The preferred stereoisomer in the formation of the five-membered ring ethers is trans, whereas in the six-membered ring ethers the cis isomer predominates. MM2 calculations help rationalize the observed stereoselectivity. The ratio of diastereomeric products from the INOC reaction appears to correlate with product stabilities. Simple heating of some of the oximino ethers led to intramolecular cycloaddition. The ring closure apparently proceeds subsequent to a tautomeric equilibration of the oxime with a transient nitrone which is trapped by the neighboring {pi}-bond.

• OSTI ID: 7071638
• Journal Information: Journal of Organic Chemistry; (USA), Journal Name: Journal of Organic Chemistry; (USA) Vol. 54:22; ISSN JOCEA; ISSN 0022-3263
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALCOHOLS
CHEMICAL REACTIONS
DATA
DATA ANALYSIS
EXPERIMENTAL DATA
FURANS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDATION
SYNTHESIS
TETRAHYDROFURAN