ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Bromination of (-)-4-hydroxy-N-methylmorphinan-6-one (3), prepared from natural morphine, with 1 mol of bromine in acetic acid, afforded the 1-bromo ketone 5. The structure of 5 was assigned by 13C-NMR.spectroscopy, and confirmed by X-ray diffraction analysis of its hydrobromide salt. It is suggested that monobromination of synthetic (±)-2,4-dihydroxy-N-formylmorphinan-6-one (7) takes in principle a similar course, although the 13C-NMR.spectrum of the primary reaction product 9 could not be measured because of insolubility in commonly used solvents. Monobromination of (-)-4-acetoxy-N-formylmorphinan-6-one (12) of the natural series, and of (±)-2,4-diacetoxy-N-formylmorphinan-6-one (8) of the synthetic series, followed by treatment of the monobrominated ketones with potassium carbonate in methanol resulted in closure of the O-bridge, and afforded after acid hydrolysis, the corresponding 4,5-epoxy-morphinan-6-ones (-)-16 and (±)-17 respectively. This variation of the ring closure reaction represents a novel and convenient method to convert 4-hydroxymorphinan-6-ones into their corresponding 4,5-epoxymorphinan-6-ones, without involving aromatic bromination and with only 1 mol of bromine.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19810640545
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