121962-99-0Relevant articles and documents
The Facility of Formation of a Δ6 Bond in Dihydromorphinone and Related Opiates
Nagase, Hiroshi,Abe, Akira,Portoghese, Philip S.
, p. 4120 - 4125 (1989)
Treatment of naltrexone, dihydromorphinone, or related opiates that contain a 6-keto group with acetic anhydride or tert-butyldimethylsilyl chloride under mild conditions afforded enol derivatives having a Δ6 bond.Naltrexone also was found to undergo the Robinson annelation reaction with methyl vinyl ketone with facility and in high yield to give the β-hydroxy ketone 3, whose stereochemistry was determined by means of 2D NMR spectroscopy.Upon acid treatment, 3 was dehydrated to the α,β-unsaturated ketone 4.Acid-catalyzed equilibration of 4 afforded the unconjugated olefin 5.These studies suggest that the Δ6 bond is more stable than one that is exocyclic to ring C of the opiate because it permits ring flattening which may partially relieve torsional ring strain.The Δ6 bond also may relieve an eclipsing interaction between a C-6 exocyclic substituent and the vicinal furan oxygen.
Facile Intramolecular O-14 - C-7 Acetyl Transfer in Opiate 14-Acetate Esters
Nagase, H.,Portoghese, P. S.
, p. 365 - 367 (1990)
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