Stereochemistry determination by NMR Residual Dipolar Couplings: application in natural products

MANUELA E. GARCÍA; ARMANDO NAVARRO-VÁZQUEZ; D. PHILIPS; C. GAYATHRI ; H. KRAKAUER ; P. STEPHENS; VIVIANA E. NICOTRA; ROBERTO R. GIL

Golden

Otro; 8th Summer School on Green Chemistry and Sustainable Energy; 2010

American Chemical Society (ACS GCI®)

In the present work we show the power of Nuclear Magnetic Resonance (NMR) ResidualDipolar Couplings (RDCs)  on the determination of the absolute stereochemistry of sixnew steroidal lactones (withanolides) from Jaborosa parviflora, a plant from theSolanaceae family.Withanolides (w.) are a group of C-28 steroids built on an ergostane skeleton in which C-22 and C-26 are appropriately oxidized in order to form a lactone, isolated from severalgenera of the plant family Solanaceae. Jaborosa Miers is a South American genusbelonging to the Solanaceae that comprises about 23 different species which grow mainlyin Argentina.