Synthesis of vinca alakaloids and realated compounds<b>98</b>. Oxidation with dimethyldioxirane of compounds containing the aspidospermane and quebrachamine ring system. A simple synthesis of (7<i>S</i>,20<i>S</i>)-(+)-rhazidigenine and (2<i>R</i>,7<i>S</i>,20<i>S</i>)-(+)-rhazidine
作者:János Éles、György Kalaus、Lajos SzabÓ、Albert LÉvai、IstvÁn Greiner、MÁria KajtÁr-Peredy、PÁl SzabÓ、Csaba SzÁntay
DOI:10.1002/jhet.5570390423
日期:2002.7
The oxidation of (-)-tabersonine (1) with dimethyldioxirane (DMD) in neutral and acidic medium gave 16-hydroxytabersonine-N-oxide (3) and the didehydrovincamine isomers 4 and 5, respectively. (+)-14,15-Didehydro-quebrachamine (7) furnished the hydroxyindolenine 9, and the pentacyclic derivative 11. (+)-Quebrachamine (8) and DMD in neutral medium gave (7S,20S)-(+)-rhazidigenine (12) which was converted
在中性和酸性介质中,用二甲基二环氧乙烷(DMD)氧化(-)-大黄碱(1)分别得到16-羟基大黄碱-N-氧化物(3)和二脱氢长春胺异构体4和5。(+)-14,15-Didehydro-quebrachamine(7)提供了羟基吲哚啉9和五环衍生物11。(+)-瓜拉巴胺(8)和DMD在中性介质中得到(7 S,20 S)-(+)-rhazidigenine(12),将其转化为(2 R,7 S,20 S)-(+)-rhazidine (13b)用盐酸。