Total Syntheses of Racemic, Natural (−) and Unnatural (+) Glyceollin I
journal contributionposted on 06.11.2008, 00:00 by Rahul S. Khupse, Paul W. Erhardt
The first total syntheses of racemic glyceollin I and its enantiomers are described. A Wittig approach was utilized as an entry to the appropriately substituted isoflav-3-ene so that an osmium tetroxide mediated asymmetric dihydroxylation could be deployed for stereospecific introduction of the 6a-hydroxy group. While using triphenylphosphine hydrobromide, a novel method was found for gently removing MOM from protected phenolic hydroxyl groups present within sensitive systems.