The Journal of Organic Chemistry

5-Unsubstituted 2-pyrrolecarboxaldehydes for porphyrin synthesis and the cyanovinyl protecting group

JB Paine III, D Dolphin

Index: Paine, John B.; Dolphin, David Journal of Organic Chemistry, 1988 ,  vol. 53,  # 12  p. 2787 - 2795

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Citation Number: 48

Abstract

(Cyanoviny1) pyrroles (13) derived from the Knoevenagel condensation of benzyl 5-formyl-2- pyrrolecarboxylates (12) with methyl cyanoacetate were employed in a facile sequence of four steps to produce, regioselectively, 5-unsubstituted 2-pyrrolecarboxaldehydea (5), important intermediates for porphyrin synthesis. Each step proceeded in 90-95% yield, making 5 available smoothly from benzyl 5-methyl-2-pyrrolecarboxylates (10) in seven ...