title: From chiral ortho-benzoquinone monoketals to nonracemic indolinocodeines through Diels-Alder and Cope reactions.
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.
authors.affiliation: Department of Chemistry, University of Waterloo Waterloo, Ontario, Canada.
authors.forename: Jihong
authors.initials: J
authors.lastname: Gao
authors.forename: Josephine
authors.initials: J
authors.lastname: Orso Simon
authors.forename: Russell
authors.initials: R
authors.lastname: Rodrigo
authors.forename: Abdeljalil
authors.initials: A
authors.lastname: Assoud