Determination of the absolute configuration of the natural product klaivanolide via density functional calculations of vibrational circular dichroism (VCD)

The absolute configuration (AC) of the antiprotozoal lactone, Klaivanolide, 1 , from Uvaria klaineana , has been determined using Vibrational Circular Dichroism (VCD) spectroscopy. The experimental VCD spectrum of the (+) enantiomer of 1 was measured. To analyze the AC of (+)‐ 1 , the conformationally‐averaged VCD spectrum of 7‐ S ‐ 1 was calculated using density functional theory (DFT) and the GAUSSIAN 03 program. The B3PW91/TZ2P conformationally‐averaged VCD spectrum of 7‐ S ‐ 1 proves that the AC of 1 is 7‐ S ‐(+). Chirality 21:E48–E53, 2009. © 2009 Wiley‐Liss, Inc.