Formation of β-lactams from tricarbonyliron lactone complexes
作者:Gary D. Annis、Elizabeth M. Hebblethwaite、Steven V. Ley
DOI:10.1039/c39800000297
日期:——
A number of tricarbonyliron lactam complexes were prepared from the corresponding lactonecomplexes by reaction with amines in the presence of ZnCl2 and on subsequent oxidation with CeIV gave β-lactams in excellent yield.
A process for the preparation of a lactam of formula:
wherein R1, R2 and R3 may be the same or different and each represents hydrogen or C1-6 alkyl, or R1 and R2 may together complete a carbocyclic ring; R4 is hydrogen, -CH -CO2RP where RP is a carboxy-protecting group, -CH2-CH2-OH or a protected derivative thereof, -CH2-CH2-CHO or a protected derivative thereof, or R3 and R4 together complete a carbocyclic ring; R4 is hydrogen or C1-6 alkyl; and R5 is hydrogen, an organic radical wherein any reactive groups may be protected or a subgroup offormula-NRαRβ wherein Rα and Rβ are the same or different and each is hydrogen or an organic radical, or a subgroup of ORδ wherein Rδ is a hydroxyl protecting group, which process comprises treatment of an iron complex of formula
with an oxidising agent.