Absolute Structure of 2'-Desacetoxyaustrospicatine Established by X-Ray analysis and Circular Dichroism Spectroscopy

Three taxane diterpenes, taxinine (1), taxinine B (2), and 2'-desacetoxyaustrospicatin (3), have been isolated from Taxus cuspidata SIEB et ZUCC. The absolute stereostructure of 3 has been determined by a combination of X-ray analysis and circular dichroism (CD) spectroscopy. Complete assignments of 1H- and 13C-nuclear magnetic resonance (NMR) signals for 1 and 2 have been made on the basis of two-dimensional (2D) NMR techniques.