title: An access to 3,4-(aminomethano)proline in racemic and enantiomerically pure form.
abstract: Protected racemic and enantiomerically pure 3,4-(aminomethano)prolines rac-9 and (2S,2'R,3R,4R)-9 have been prepared applying a titanium-mediated reductive cyclopropanation as a key step. Thus, cyclopropanations of N,N-dibenzylformamide with titanacyclopropanes generated in situ from racemic or enantiomerically pure tert-butyl N-Boc-3,4-dehydroprolinates rac-8 or (S)-8 proceed diastereoselectively, and furnish the protected racemic and enantiomerically pure diamino acid 9. The latter was incorporated into three tripeptides containing glycyl, alanyl and phenylalanyl moieties.
authors.affiliation: Institut für Organische und Biomolekulare Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany.
authors.forename: Farina
authors.initials: F
authors.lastname: Brackmann
authors.forename: Heiko
authors.initials: H
authors.lastname: Schill
authors.forename: Armin
authors.initials: A
authors.lastname: de Meijere
mesh_terms: D018360:Crystallography, X-Ray; D008744:Methylamines / Q000138:chemical synthesis / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D011392:Proline / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C509474:3,4-(aminomethano)proline; D008744:Methylamines; D011392:Proline