Planta Med 2016; 82 - PC84
DOI: 10.1055/s-0036-1578786

Stereoselective Syntheses Of Phytoestrogenic Isofavans

C Yalamanchili 1, 2, S Chandra Kumar Rotte 1, AG Chittiboyina 1, IA Khan 1, 2
  • 1National Center for Natural Products Research
  • 2Division of Pharmacognosy, Department of BioMolecular Science, School of Pharmacy, University of Mississippi, University, Mississippi, 38677, United States

Stereoselective syntheses of isoflavans were performed using Evans' enantioselective aldol condensation as a key step to introduce the chirality at C-3 position of an isoflavan scaffold. Chiral isoflavan, (-)-equol, a metabolite of the soy isoflavones, formononetin 1 and daidzein 2, is produced by intestinal bacteria in some, but not all, adults. Both enantiomers are of interest from a clinical and pharmacological perspective and are currently being developed as nutraceutical and pharmacological agents. For the first time, both antipodes of equol 4 and sativan 5 were synthesized in > 98% ee with good overall yields starting from commercially available starting materials. The same methodology can be applied for syntheses of other C-3 chiral isoflavans and the details of the synthetic methodology will be discussed.

Fig. 1

Acknowledgements: The United States Department of Agriculture, Agricultural Research Service, Specific Cooperative Agreement No. 58 – 6408 – 1-603 – 07 and the University of Illinois Botanical Research Center (BRC) entitled "Botanical Identification, Characterization, Quality Assurance and Quality Control", funded by NIH, Prime award number 1P50AT006268 – 05.