The addition of heterocyclic amines to a nitro-alkene : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University

Abstract

This thesis is concerned with the synthesis of analogues of the insect feeding deterrent peramine (1), in which the key step involves the use of a Michael addition to a nitro-alkene. The introduction therefore consists of three parts:

1. The isolation and synthesis of the insect antifeedant perarnine (1). 2. The use of nitro-alkenes as Michael acceptors. 3. Pyrazine ring systems related to peramine (1) and other natural products.

1.1 The Isolation and Synthesis of the Insect Antifeedant Peramine (1).

The resistance of perennial ryegrass Lolium perenne L to the Argentine stem weevil Listrontus bonariensis arises from the principal insect feeding deterrent peramine (1), a pyrrolopyrazine alkaloid produced by the fungal endophyte Acremonium lolii 1. The Argentine stem weevil is a major pest of ryegrass pastures, maize, wheat, barley, and brassica crops in New Zealand. The adult Argentine stem weevil produces window like grazing scars on leaves, but generally causes little permanent damage to established pastures. The larvae however, are more destructive. Eggs are laid on the leaf sheath tissue and hatch to produce tunnelling larvae that burrow into the middle of the grass tiller. The larvae can also transfer from tiller to tiller, killing from three to five tillers as they mature. It has been shown that endophyte infected grass suffers less damage by adult weevil and has fewer eggs and larvae than do the uninfected plants. [From Introduction]