The first enantioselective synthesis of poly-oxygenated α-hydroxydihydrochalcones and circular dichroic assessment of their absolute configuration

✍ Scribed by Barend C.B. Bezuidenhoudt; Annelie Swanepoel; Jan A.N. Augustyn; Daneel Ferreira

• Publisher: Elsevier Science
• Year: 1987
• Tongue: French
• Weight: 213 KB
• Volume: 28
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)96644-9

✦ Synopsis

Epoxidation of 4-methoxy-2' ,4'-dimethoxymethyl-(El-chalcone with H207_ in the presence of poly-a-aminoacid catalysts afforded zhiral aromatic -oxygenated chalcone epoxides.

These were transformed into the corresponding a-hydroxydihydrochalcones and their absolute configurations determined by c-a. spectroscopy.

One of these was proved to be identical to a novel aRanalogue from Pericopsis elata. Despite the availability of non-and mono-oxygenated chalcone epoxides in high optical yields,le8 utilisation of these versatile precursors in synthesis of flavonoids and isoflavonoids is restricted to a single fortuitous trans-formation3 into an aromatic deoxy a-hydroxydihydrochalcone. Although several members 9-13 of tine latter rare group of natural products, with their close biogenetic relationship to isoflavonoids, have been identified since the isolation 13 of racemic nubigenol, progress in the chemistry of these