title: Stereoselective iodocyclization of (S)-allylalanine derivatives: gamma-lactone vs cyclic carbamate formation.
abstract: An efficient procedure for highly chemo- and stereoselective cyclization of (S)-allylalanine derivatives is reported (diastereomeric ratios up to 96:4) where the reaction course can be completely controlled by switching from gamma-lactones to cyclic carbamates simply with the proper choice of the amino acid protecting groups. Both processes are stereoconvergent and afford the (S,S)-products in high yields, short reaction times, and mild reaction conditions.
authors.affiliation: Dipartimento di Scienze Chimiche and ITM-CNR, Università di Padova, via Marzolo 1, I-35131 Padova, Italy.
authors.forename: Mariella
authors.initials: M
authors.lastname: Pattarozzi
authors.forename: Cristiano
authors.initials: C
authors.lastname: Zonta
authors.forename: Quirinus B
authors.initials: QB
authors.lastname: Broxterman
authors.forename: Bernard
authors.initials: B
authors.lastname: Kaptein
authors.forename: Rita
authors.initials: R
authors.lastname: De Zorzi
authors.forename: Lucio
authors.initials: L
authors.lastname: Randaccio
authors.forename: Paolo
authors.initials: P
authors.lastname: Scrimin
authors.forename: Giulia
authors.initials: G
authors.lastname: Licini
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry*; D002219:Carbamates / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D003500:Cyclization; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism
chemical_list: D002219:Carbamates; D007783:Lactones; D000409:Alanine