Synthesis of vinca alakaloids and realated compounds 98. Oxidation with dimethyldioxirane of compounds containing the aspidospermane and quebrachamine ring system. A simple synthesis of (7S,20S)-(+)-rhazidigenine and (2R,7S,20S)-(+)-rhazidine

✍ Scribed by János Éles; György Kalaus; Lajos SzabÓ; Albert LÉvai; IstvÁn Greiner; MÁria KajtÁr-Peredy; PÁl SzabÓ; Csaba SzÁntay

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2002
• Tongue: English
• Weight: 62 KB
• Volume: 39
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570390423

✦ Synopsis

Abstract

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 (7__S__,20__S__)‐(+)‐rhazidigenine (12) which was converted to (2__R__,7__S__,20__S__)‐(+)‐rhazidine (13b) with hydrochloric acid.