title: Doubly diastereoselective [3,3]-sigmatropic aza-Claisen rearrangements.
abstract: The doubly diastereoselective [3,3]-sigmatropic aza-Claisen rearrangement of silylketene aminals derived from 5-substituted (3S,4E,alphaR)-1-benzyloxy-3-[N-acyl-N-(alpha-methylbenzyl)amino]pent-4-enes furnishes 2,3-disubstituted (R)-N-alpha-methylbenzyl (2S,3R,4E)-7-benzyloxyhept-4-enamides in >90% de under the "matched" control of both stereogenic centres. Rearrangement of the "mismatched" diastereomeric (3R,4E,alphaR)-substrates proceeds with low diastereoselectivity. The substrate scope of the doubly diastereoselective rearrangement of the "matched" substrates in which two new stereogenic centres are created has been delineated.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK. steve.davies@chem.ox.ac.uk
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Davies
authors.forename: A Christopher
authors.initials: AC
authors.lastname: Garner
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Nicholson
authors.forename: James
authors.initials: J
authors.lastname: Osborne
authors.forename: Paul M
authors.initials: PM
authors.lastname: Roberts
authors.forename: Edward D
authors.initials: ED
authors.lastname: Savory
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Smith
authors.forename: James E
authors.initials: JE
authors.lastname: Thomson