The synthesis of porphyrin precursors requires the successive introduction of substituents at the pyrrole α-and α'-positions (2-and 5-, respectively). An α-pyrrole substituent that serves as a temporary masking agent and is not deactivating would greatly facilitate such syntheses, particularly for β-(3, 4)-unsubstituted pyrroles, but has heretofore not been available. A series of α-RS groups (R= Me, Et, n-decyl, Ph) have been investigated in this regard, ...
