Synthesis of a linear α-hydroxymethyl-pentapyrrole derivative and its cyclization to uroporphyrinogens
摘要:
A linear pentapyrrole bearing alpha-hydroxymeythyl group in the terminal was synthesized by the stepwise coupling of alpha-free pyrrole with azafulvenium ion 6. When it was treated with a catalytic amount of p-toluensulfonic acid under anaerobic condition, followed by aerial oxidation of the products, a statistical mixture of uroporphyrin I-IV octamethyl eaters was obtained. It is proposed that this transformation proceeds through a spiro-pyrrolenine as a key intermediate. (C) 2000 Elsevier Science Ltd. All rights reserved.
Synthesis of a linear α-hydroxymethyl-pentapyrrole derivative and its cyclization to uroporphyrinogens
摘要:
A linear pentapyrrole bearing alpha-hydroxymeythyl group in the terminal was synthesized by the stepwise coupling of alpha-free pyrrole with azafulvenium ion 6. When it was treated with a catalytic amount of p-toluensulfonic acid under anaerobic condition, followed by aerial oxidation of the products, a statistical mixture of uroporphyrin I-IV octamethyl eaters was obtained. It is proposed that this transformation proceeds through a spiro-pyrrolenine as a key intermediate. (C) 2000 Elsevier Science Ltd. All rights reserved.