title: Novel fragmentation reaction of correolide.
abstract: [reaction: see text] Pentacyclic triterpenoid natural product correolide (1) was converted to ketone 2 via ozonolysis. An unusual fragmentation reaction of ketone 2 with LiCl was discovered. This reaction is general among several similar substrates examined and appears to be specific for the correolide-type E-ring structure (ketone). A mechanism involving a retroaldol reaction, a nucleophilic opening of the epoxide, and a subsequent acetoxy elimination reaction was proposed.
authors.affiliation: Department of Medicinal Chemistry, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, USA. bao_jianming@merck.com
authors.forename: Jianming
authors.initials: J
authors.lastname: Bao
authors.forename: Robert K
authors.initials: RK
authors.lastname: Baker
authors.forename: George A
authors.initials: GA
authors.lastname: Doss
authors.forename: Frank
authors.initials: F
authors.lastname: Kayser
authors.forename: Andrew
authors.initials: A
authors.lastname: Kotliar
authors.forename: Shouwu
authors.initials: S
authors.lastname: Miao
authors.forename: William H
authors.initials: WH
authors.lastname: Parsons
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Rupprecht