Reassignment of the Configuration of Several Keto-cyclolignans Prepared from Podophyllotoxin

✍ Scribed by José María Miguel del Corral; Marina Gordaliza; José-Luis López; Esther Del Olmo; M. Angeles Castro; M. Luisa López

• Book ID: 102255340
• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: German
• Weight: 185 KB
• Volume: 78
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19950780713

✦ Synopsis

The configuration of several keto-cyclolignans reiated to podophyllotoxin has been reviewed. Under basic catalysis, the configuration at the C-atom in a -position to the lactone carbonyl group in podophyllotoxone is inverted instead of the C-atom in a-position to the ketone group, as it has been reported.

Last year, in a paper published in this Journal, Hoyert and Matusch reported a 'novel rearrangement of podophyllotoxone' [ 11. They described the epimerization of podophyllotoxone (1) at C(3) a to the C(4)=0, and the formation of isopicropodophyllone (2), in equilibrium with 1, when treating the former substance with BuLi in refluxing Et,O. Subsequently, preparation of the unsaturated keto-acid 3 and several other derivatives were reported.