Stereoselective iodocyclization of (S)-allylalanine derivatives: gamma-lactone vs cyclic carbamate formation.
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.
Pattarozzi
Mariella
M
Dipartimento di Scienze Chimiche and ITM-CNR, Università di Padova, via Marzolo 1, I-35131 Padova, Italy.
Zonta
Cristiano
C
Broxterman
Quirinus B
QB
Kaptein
Bernard
B
De Zorzi
Rita
R
Randaccio
Lucio
L
Scrimin
Paolo
P
Licini
Giulia
G
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
D002219:Carbamates; D007783:Lactones; D000409:Alanine