Methyl 2-undecynoate has a powerful, waxy, green, floral odor
with a sweet flavor reminiscent of violet. May be prepared by
methylation of the corresponding acid at the boil in the presence
of HCL or at room temperature in the presence of H2S04; the acid
can be prepared from methyl nonyl ketone by reaction with phosphorous
pentachloride, which yields the acetylenic compound;
treatment of this with potassium carbonate yields undecyne, which
is then converted to the acid by treatment with Na and methyl
chlorocarbonate.