Corey EJ,
*,
Wu Y.-J.
Harvard University, Cambridge, USA
Total Synthesis of (±)-Paeoniflorigenin and Paeoniflorin.
J. Am. Chem. Soc. 1993;
115: 8871-8872
DOI:
10.1021/ja00072a063
Key words
(±)-paeoniflorigenin -
Paeonia lactiflora
- Prilezhaev reaction - Reformatsky-type cyclization
Significance
In 1993, Corey and Wu reported the synthesis of (±)-paeoniflorigenin, a natural product
from the roots of paenia lactiflora, which are widely used in traditional Chinese medicine. The approach relies on oxidative
annulation of dihydro-m-cresol ether A and SmI2-induced, Reformatsky-type cyclization from an α-chloro nitrile.
Comment
The synthesis commenced with annulation of A and B to give γ-lactone C. Chlorination followed by Prilezhaev epoxidation yields E. Cyclization is achieved by treating lactol F with an excess of TMS-triflate. Exposure of H to SmI2 leads to formation of the carbon skeleton of paeniflorigenin. Protection of the secondary
alcohol followed by reduction of the nitrile gives K. Benzoylation and global deprotection completed the total synthesis of (±)-paeniflorigenin
in 13 steps from A.
