116222-73-2Relevant academic research and scientific papers
REGIOSELECTIVE CHLORINATION OF VALINE DERIVATIVES
Bowman, Nigel J.,Hay, Michael P.,Love, Stephen G.,Easton, Christopher J.
, p. 259 - 264 (2007/10/02)
Reaction of N-benzoylvaline methyl ester (5a) with sulphuryl chloride gave the β-chlorovaline derivative (6a) and lesser amounts of diastereoisomers of the γ-chlorovaline derivative (7a).A similar mixture of products was obtained throuch photolysis of the N-chloroamide (13).The reactions of the valine derivatives (5a) and (13) involve regioselective intermolecular transfer of the β-valinyl hydrogen.There is no evidence for reaction at the α-position.The β-chloroalanine derivative (23) was produced through reaction of N-benzoylalanine methyl ester (17a) with sulphuryl chloride and by photolysis of the N-chloroamide (22).Chlorination of the azetidinone (16a) gave (16b) in modest yield.These reactions establish the chemical validity of a regiospecific hydrogen-atom abstraction proposed in penicillin biosynthesis.
