| dc.description.abstract | The thesis consists of two parts of study.
The first part describes a chromatographic analysis
of a sample of Kenyan beeswax (honeybee, Armis
mellifera L.) and, in particular, its I-triacontanol
(1) content. The physico-chemical properties of the
wax were first determined using standard analytical
procedures. The composition of the saponified wax
was ascertained by column chromatography, thin-layer
chromatography and infrared spectroscopy. By use of
gas chromatography, the content of I-triacontanol in
the beeswax was determined and found to constitute
21.4% of the whole wax.
The second part of the thesis describes a new
approach to the synthesis of I-triacontanol starting
from tetracosanoic acid (33). In a model synthesis
study, stearic acid (28) was converted to tetracosanoic
acid by addition of a six carbon unit through the
silyl enol ether synthon, l-cyclohexenyloxytrimethyl-
-silane (76). Stearic acid was converted to -'
stearoyl chloride (25) which then underwent specific
coupling (C-acylation) with the silyl enol ether 76
via both Lewis acid catalysis (zinc(II) bromide in
dichloromethane) and base catalysis (triethylamine
in tetrahydrofuran) to give 2-stearoylcyclohexanone
(31). Re-arrangement of 31 using alcoholic
potassium hydroxide followed by hydrazine reduction
and subsequent hydrolysis gave tetracosanoic acid.
Both coupling reactions gave comnarable yields of
the product and were employed for the synthesis of
I-triacontanol. Tetracosanoic acid was thus
converted to triacontanoic acid (20). Methylation
of 20 followed by reduction with lithium aluminium
hydride in tetrahydrofuran afforded I-triacontanol
in 24% overall yield. | en |
