Pure Appl. Chem., 2003, Vol. 75, No. 9, pp. 1263-1275
doi:10.1351/pac200375091263
Tandem allylboration-ring-closing metathesis reactions for the preparation of biologically active molecules*
P. Veeraraghavan Ramachandran, M. Venkat Ram Reddy, and Herbert C. Brown
Herbert C. Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
Abstract:
The development of asymmetric synthesis during the past two decades aided organic chemists considerably in the synthesis of complex natural products. Organoborane chemistry continues to play an important role in asymmetric synthesis. One of the important reactions that has become very common in the arsenal of synthetic chemists is allylboration and related reactions. Another important reaction that has recently attained enormous importance in organic chemistry is the ring-closing metathesis (RCM) reaction. Indeed, a combination of allylboration and RCM reactions provides an excellent route to cyclic ethers, lactones, lactams, etc. Herein, we describe a sequential asymmetric allylboration and RCM reaction protocol that has been utilized for the synthesis of several alpha-pyrone-containing natural products,particularly biologically active molecules.
*Lecture presented at the XIth International Meeting on Boron Chemistry (IMEBORON XI), Moscow, Russia, 28 July - 2 August 2002. Other presentations are published in this issue, pp. 1157-1355.