Title
5-epi-Incensole: synthesis, X-ray crystal structure and absolute configuration by means of ECD and VCD studies in solution and solid state
Author
Satya Kumar Avula, Hidayat Hussain, René Csuk, Sven Sommerwerk, Phil Liebing, Marcin Górecki, Gennaro Pescitelli, Ahmed Al-Rawahi, Najeeb Ur Rehman, Ivan R. Green, Ahmed Al-Harrasi
Year
2016
Journal
Tetrahedron: Asymmetry
Abstract
Incensole 1 and its acetate 2, found in incense, demonstrate interesting biological activities. Incensole acetate 2 was prepared on a large scale by employing the Paul and Jauch protocol from the crude extracts of Boswellia papyrifera Hochst. 5-epi-Incensole 3, obtained as colorless crystals, was prepared from incensole acetate via three steps; deacetylation, oxidation and reduction. The structure of 5-epi-incensole 3 was elucidated by means of spectroscopic data analysis, and the absolute configuration was established by single crystal X-ray analysis in combination with electronic and vibrational circular dichroism. In particular, the applicability of the solid-state ECD/TDDFT protocol to a compound with only two non-conjugated alkene chromophores was verified.
Instrument
J-715
Keywords
Circular dichroism, Absolute configuration, Natural products, Medicinal