Biosynthesis of porphyrins and related macrocycles. Part VIII. Enzymic decarboxylation of uroporphyrinogen-III: structure of an intermediate, phyriaporphyrinogen-III, and synthesis of the corresponding porphyrin and of two isomeric porphyrins

Abstract

Bei der Incubierung von Porphobilinogen (I) mit einem Enzym‐System aus Vogel‐Erythrocyten wird Phyriaporphyrin‐III′ gebildet, für das die Struktur (IIb) ermittelt wird: Von den 4 möglichen Strukturen (IIa)‐(IIIb) für dieses Porphyrin können 2 [(IIIa) und (IIIb)] durch Versuche mit "C‐dotiertem (I) und 13C‐NMR‐ Analyse des erhaltenen Produkts ausgeschlossen werden.

An efficient route to vinylporphyrins

“…The orange crystals were filtered, washed with methanol, and air dried. Yield 19 gin two crops (79%), mp 146°C (dec.); 'H nmr (CDC13/TFA) 6: 1.18 (t, 3H, J = 7.5 HZ, CH2CH3), 2.00 (s, 3H, CH3), 2.04 (s, 3H, CH3), 2.35 (s, 3H, COCH3), 2.65 (s, 3H, CH3), 2.75 (m, overlap, 4H, CH2CH3 and CH2CH20-), 4.10 (t, 2H, J = 6.5 Hz, CHrCH20-), 6.80 1H,bridgeCH),7.45(d,1H,J=3.2Hz,pyr-H Acetoqethy1)-3' -[(methoqcarbonyl)ethyl]-3,4', 5-trimethyl-2,2' -dipyrromethene hydrobromide (40) The pyrrole 32 (25). (1.35 g, 4.3 mmol) in THF (35 mL) containing triethylamine (5 drops) and 10% Pd-C (140 mg) was hydrogenated as described above.…”

“…The a,P-diunsubstituted pyrrole 18 necessary for the synthesis of the dipyrromethene 21 was obtained from pyrrole 11 (Scheme 3), which in turn was prepared from benzyl acetoacetate and diethyl 3-oxopentanedioate as described earlier (25). Following catalytic debenzylation using 10% Pd-C, the resulting pyrrole-4-carboxylic acid (12) was decarboxylated by an indirect iodinative-deiodinative procedure (the electron-withdrawing 2-ethoxycarbonyl group prevents direct decarboxylation) to give the P-unsubstituted pyrrole (14) in 60% overall yield (from 11).…”

“…The common monopyrrolic precursor 33 was prepared starting from 4-(methoxycarbonyl)methylpyrrole 9, by diborane reduction to 4-(2-hydroxyethy1)pyrrole 31, protecting as the 4-(2-acetoxyethyl) derivative (32) followed by catalytic debenzylation of the a-ester group. 2-Formyl-3-ethyl-4-methylpyrrole (19) (23) and 2-formyl-3-(2-methoxycarbonyl)ethylpyrrole (38) (25) were synthesized according to literature procedures. Acid-catalyzed condensation of the pyrrole pairs 19,33 and 38,33 afforded the dipyrromethenes 39 and 40 in high yield.…”

Synthèse de méso-α,γ bis(diamino-2,6 phényl) porphyrines

“…Le pyrrole 26 est transform6 en pyrrole l a selon la mCthode de McDonald et al (8): l'oxydation du pyrrole 26 par 3 Cquivalents de chlorure de sulfuryle, suivie d'un traitement a 1'Cthanol conduit au diester 2c dont l'hydrogknolyse fournit l'acide 2d. La dkcarboxylation de l'acide 2d selon la methode de Battersby et al (9) conduit au pyrrole l a qui est transestkrifik en pyrrole 16. Le rendernent global du pyrrole lb a partir du malonate d'kthyle est de 18%.…”

“…Diace'tamido-2,6 benzalde'hyde (12): M , Cl lHIZN203 = 220; ir (CHCl,): 1700, 1670, 1617, 1597 crn-I; (KBr): 3300-3285, 1700, 1685, 1645, 1620, 1600 cm-'; rmn (CDC13): 9,86 (s, IH), 7 3 3 (rn, 3H), 2,15 (s, 6H); rmn (Me2CO): 10,3 (s large s'Cchange avec D20), 9,8 (s,IH),7,6 (m,3H), 2,06 (s, 6H); sm: 220, 192 (-CO), 177 (-CH3), 150 (-CH2CO), 108 (-CH2CO). Anal.…”