title: Combined epimerisation and acylation: Meerwein-Ponndorf-Verley-Oppenauer catalysts in action.
abstract: A practical racemisation-epimerisation method for chiral secondary alcohols has been developed. Meerwein-Ponndorf-Verley-Oppenauer catalysts such as neodymium(III) isopropoxide are able to racemise these alcohols with retention of other stereocentres in the molecule. This is particularly useful for the recycling of the undesired products of kinetic resolutions of alcohols. By combination of such a racemisation with an acylation using isopropenyl or ethoxyvinyl esters as acyl donors, a fast straightforward recycling of starting materials may be achieved. The combined epimerisation and acylation process is demonstrated for the steroid estradiol methyl ether.
authors.affiliation: Gebouw voor Scheikunde, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
authors.forename: Dirk
authors.initials: D
authors.lastname: Klomp
authors.forename: Kristina
authors.initials: K
authors.lastname: Djanashvili
authors.forename: Nina Cianfanelli
authors.initials: NC
authors.lastname: Svennum
authors.forename: Nuttanun
authors.initials: N
authors.lastname: Chantapariyavat
authors.forename: Chung-Sing
authors.initials: CS
authors.lastname: Wong
authors.forename: Filipe
authors.initials: F
authors.lastname: Vilela
authors.forename: Thomas
authors.initials: T
authors.lastname: Maschmeyer
authors.forename: Joop A
authors.initials: JA
authors.lastname: Peters
authors.forename: Ulf
authors.initials: U
authors.lastname: Hanefeld