Pub No:
221
Title:
5-Unsubstituted-2-Pyrrolecarboxaldehydes for Porphyrin Synthesis and the Cyanovinyl Protecting Group
Authors:
Paine, J.B. III and David Dolphin
Journal:
J. Org. Chem.
Year:
1988
Pages:
53, 2787-2795
Abstract:
(Cyanovinyl)pyrroles I (R = Me, R1 = Et, octyl; R = Et, R1 = Me) derived from the Knoevenagel condensation of benzyl 5-formyl-2-pyrrolecarboxylates with NCCH2CO2Me were employed in a facile sequence of 4 steps to produce, regioselectively, 2-pyrrolecarboxaldehydes II, important intermediates for porphyrin synthesis. Each step proceeded in 90-95% yield, making II available smoothly from benzyl 5-methyl-2-pyrrolecarboxylates in 7 steps, with an overall yield of 66-72%.

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