title: Synthesis of [6,n] cis-fused ring compounds via Cr-mediated dearomatisation-ring-closing metathesis.
abstract: cis-Fused [6,8], [6,7], [6,6] and [6,5] ring systems containing a cyclohexadiene ring unit, a cycloenone ring and a quaternary carbon at the ring junction were obtained in only two steps from [Cr(CO)3(eta6-p-methoxyphenyl oxazoline)]. The sequence proceeds via diastereoselective addition of three C-substituents across an arene double bond, followed by allylation and ring closing metathesis (RCM). RAMP-hydrazone and (R)-isopropyloxazoline were used as chiral auxiliaries to provide, after removal of the auxiliaries, the enantiomerically highly enriched [6,7] cis-fused system.
authors.affiliation: Department of Organic Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland. peter.kundig@chiorg.unige.ch
authors.forename: E Peter
authors.initials: EP
authors.lastname: Kündig
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bellido
authors.forename: Krishna P
authors.initials: KP
authors.lastname: Kaliappan
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Pape
authors.forename: Sylvie
authors.initials: S
authors.lastname: Radix