C8-selective biomimetic transformation of 5,7-dihydroxylated flavonoids by an acid-catalysed phenolic Mannich reaction: Synthesis of flavonoid alkaloids with quercetin and (–)-epicatechin skeletons
作者:Viktor Ilkei、András Spaits、Anita Prechl、Judit Müller、Árpád Könczöl、Sándor Lévai、Eszter Riethmüller、Áron Szigetvári、Zoltán Béni、Miklós Dékány、Ana Martins、Attila Hunyadi、Sándor Antus、Csaba Szántay、György Tibor Balogh、György Kalaus、Hedvig Bölcskei、László Hazai
DOI:10.1016/j.tet.2017.01.068
日期:2017.3
8-(2″-pyrrolidinon-5″-yl)-(–)-epicatechin. These known natural products were prepared via an acid-catalysed regioselective phenolic Mannich reaction involving the electrophilic attack of an N-acyliminium ion on the corresponding flavonoidal precursors. The products were purified by preparative HPLC. The reactions showed high C8-regioselectivity. The major isomers of the synthesized flavonoid alkaloids