UBC Theses and Dissertations
Studies on the biosynthesis of trichothecin Forrester, James McLeod
The derivation of trichothecin (28) from Ɣ-bisabolene (34) is discussed and the contradictory results of two research groups noted. Radioactive [symbol omitted]-bisabolol (35) was prepared by reaction of radioactive methyl magnesium iodide on ketone (42) which was prepared by a modification of a literature procedure. Thus Diels-Alder addition of isoprene (1) and acrylic acid gave acid (41). The structure of the lactone prepared by treatment of this acid with 98% formic acid is corrected to lactone (64) and not lactone (62). Bromide (38) was prepared by a literature procedure from methyl cyclopropyl ketone (44). Addition of the acid chloride of acid (41) to the Grignard complex of bromide (38) gave ester (70) which on treatment with ethereal methyl lithium solution followed by Jones oxidation gave ketone (42). Radioactive [symbol omitted]-bisabolol (34) was then prepared from ketone (42) by reaction with radioactive methyl magnesium iodide, and fed to Trichothecium roseum. Isolation of trichothecin (28) showed an incorporation of 0.014%. Degradation of trichothecin (28) to trichothecolone (29) showed a significant decrease in radioactivity, the significance of which is then discussed.
Item Citations and Data