1.
J Org Chem
; 78(1): 48-58, 2013 Jan 04.
Article
in English
| MEDLINE
| ID: mdl-22967240
ABSTRACT
The S-dienol (-)-4 containing 10 carbons and one oxygen of the final product was prepared in 98.6% ee and 39% yield from cyclohexan-1,3-dione. It was attached to the aromatic ring as a monoether of catechol S-(-)-6 and subsequently subjected to oxidative ketalization in methanol. The allylated phenanthrofuran obtained was selectively oxidized at the terminal double bond. The fifth ring was completed by a "one-pot" amidation-cyclization process promoted by palladium acetate. The final homochiral indolinocodeine (-)-31 was obtained in 16 steps and 3.6% overall yield from cyclohexan-1,3-dione.