title: The aza-
abstract: The inclusion of a C-2 trialkylsilyl substituent into allylic amine precursors allows the base-induced aza-[2,3]-Wittig sigmatropic rearrangement to proceed in excellent yield and diastereoselectivity. The rearrangement precursors require a carbonyl-based nitrogen protecting group that must be stable to the excess of strong base required for the reaction. The N-Boc and N-benzoyl group are very good at stabilizing the product anion and initiating deprotonation. The migrating groups (G) need to stabilize the intial anion by resonance and require G-CH(3)() pK(a) > 22 in order for the initial anion to be reactive enough for rearrangement. Products 7, 20b-d,f,g, and 23 are formed with high (10-20:1) anti diastereoselectivity. Product 23 containing the morpholine amide group is useful for preparing other carbonyl derivatives.
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, U. K.
authors.initials: JC
authors.lastname: Anderson
authors.initials: A
authors.lastname: Flaherty
authors.initials: ME
authors.lastname: Swarbrick