Transition Metal-Mediated Higher-Order Cycloaddition Reactions: Application To The Total Synthesis Of Complex Natural Products

摘要

ABSTRACTTRANSITION METAL-MEDIATED HIGHER-ORDER CYCLOADDITION REACTIONS: APPLICATION TO THE TOTAL SYNTHESIS OF COMPLEX NATURAL PRODUCTSbyBILAL ABOU ALEIWIOctober 2010Advisor: Dr. James H. RigbyMajor: Chemistry (Organic)Degree: Doctor of PhilosophyChromium (0)-mediated [6ð + 2ð] and [6ð + 2ð + 2ð] cycloaddition reactions between cyclic trienes and alkynes is reported. The development, investigation and the application of these reactions in the total synthesis of complex ring systems and natural products is described. Two natural products, namely, ∆ 9(12) -Capnellene and Echinopines A and B were targeted.An investigation led to the successful development of a methodology to form the linear triquinane ring system of the natural product ∆ 9(12) -Capnellene. This methodology relies mainly on a tandem Chromium (0)-mediated [6ð + 2ð] cycloaddition reaction and a radical cyclization reaction.