Synthetic and biosynthetic studies of porphyrins. Part 2. Synthesis of isopempto- and isochlorocruoro-porphyrins

Abstract

Isopempto- and isochlorocruoro-porphyrin dimethyl esters have been prepared by application of the MacDonald porphyrin synthesis. The vinyl group was introduced by elimination of hydrogen chloride from chloroethyl side-chains carried through from an intermediate pyrrole, and the formyl group (of isochlorocruoroporphyrin) was introduced at the porphyrin stage with butyl dichloromethyl ether in the presence of tin(IV) chloride.