1. Studies towards the total synthesis of azadirachtin
- Author
-
Gutteridge, C. E.
- Subjects
547.7 - Abstract
This thesis describes several strategies which have been investigated for the construction of the C8-14 bond of the natural product azadirachtin, and is presented in three principal sections. The first introduction section reviews the properties of the molecule, its biosynthesis and reported synthetic studies. Following is a detailed discussion of the known chemistry at the key reaction sites, C8 and C14. The second section describes the development of a number of intramolecular coupling strategies designed to unite the two advanced intermediates of our proposed synthesis , and is further divided into four chapters. The first describes manipulation of these molecules, previously synthesised in our laboratory, into forms useful for coupling studies; specifically substitution of the left-fragment with a heteroatom at C8. The second describes a number of potential routes to the C8-14 bond using reductive radical chemistry, proposing generation of a radical at one of the two sites followed by cyclisation onto the other to form the key bond. The viability of several related strategies has been shown by successful carbon-carbon bond formation in model systems. The third deals with the development of novel strategies using oxidative radical chemistry, generating the initial radical from a silyl enol ether component for trapping onto the second fragment. Again the concept has been validated in model studies. The last describes an approach based upon carbene insertion chemistry.
- Published
- 1996