title: alpha-t-butyl- and alpha-i-propyl-ortho-hydroxybenzylamines: racemic synthesis/resolution and asymmetric synthesis.
abstract: Efficient routes to alpha-tert-butyl- and alpha-iso-propyl-ortho-hydroxybenzylamines 1a and 1b are described. Highly enantioenriched 1a and 1b were obtained by resolution of the methoxy derivatives 2 by recrystallization of the salts formed with mandelic acid followed by Lewis acid mediated demethylation. The chiral 1,3-amino alcohol 1a has also been obtained in an asymmetric synthesis with the key step a diastereoselective alkylation of the imine obtained by condensation of o-anisaldehyde with phenyl glycinol. The absolute stereochemistry of these 1,3-aminophenols was determined by CD spectroscopy of the salicylideneamines 12 and by an X-ray structure analysis of the salt formed between (R)-mandelic acid and (S)-alpha-tert-butyl-ortho-methoxybenzylamine ((S)-2a).
authors.affiliation: Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Bernardinelli
authors.forename: D
authors.initials: D
authors.lastname: Fernandez
authors.forename: R
authors.initials: R
authors.lastname: Gosmini
authors.forename: P
authors.initials: P
authors.lastname: Meier
authors.forename: A
authors.initials: A
authors.lastname: Ripa
authors.forename: P
authors.initials: P
authors.lastname: Schüpfer
authors.forename: B
authors.initials: B
authors.lastname: Treptow
authors.forename: E P
authors.initials: EP
authors.lastname: Kündig