title: Efficient regioselective ring opening of activated aziridine-2-carboxylates with [(18)f]fluoride.
abstract: Aziridines can undergo a range of ring-opening reactions with nucleophiles. The regio- and stereochemistry of the products depend on the substituents on the aziridine. Aziridine ring-opening reactions have rarely been used in radiosynthesis. Herein we report the ring opening of activated aziridine-2-carboxylates with [(18)F]fluoride. The aziridine was activated for nucleophilic attack by substitution of various groups on the aziridine nitrogen atom. Fluorine-18 radiolabelling was followed by ester hydrolysis and removal of the activation group. Totally regioselective ring opening and subsequent deprotection was achieved with tert-butyloxycarbonyl- and carboxybenzyl-activated aziridines to give α-[(18)F]fluoro-β-alanine in good radiochemical yield.
authors: Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej 9, 2100 Copenhagen Ø (Denmark) ; Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej 9, 2100 Copenhagen Ø (Denmark).
authors: Christina
authors: C
authors: Schjoeth-Eskesen
authors: Department of Drug Design & Pharmacology, University of Copenhagen Universitetsparken 2, 2100 Copenhagen Ø (Denmark).
authors: Paul Robert
authors: PR
authors: Hansen
authors: Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej 9, 2100 Copenhagen Ø (Denmark) ; Cluster for Molecular Imaging, Faculty of Health Sciences, University of Copenhagen Blegdamsvej 3B, 2100 Copenhagen Ø (Denmark).
authors: Andreas
authors: A
authors: Kjaer
authors: Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej 9, 2100 Copenhagen Ø (Denmark).
authors: Nic
authors: N
authors: Gillings
keywords: aziridines; fluorine-18; radiochemistry; regioselectivity; ring opening