Guignardianone A

Experimental details:

IR and VCD spectra were recorded with a Bruker Tensor 27 IR spectrometer fitted with a PMA 50 module containing one photoelastic modulator, with 4 1/cm resolution, and the instrument was optimized at 1400 1/cm in a 100 μm pathlength cell with BaF2 windows. The IR (16 scans, 4000–900 1/cm) and VCD (260 min accumulation time, 1800–900 c1/m) spectra were recorded in CCl4 solution (all esters) and CDCl3 solution (both acids) with concentrations between 0.1 and 0.2 1/molL.