"Steve B" > wrote in message news:<bSgob.49946$9E1.213345@attbi_s52>...
> ... A small correction, Roy. The equation should be:
>
> CH3CH2OH + CH3COOH ----> CH3CH2OC(O)CH3 + H2O
>
> Your equation shows methyl propionate as the product, not ethyl acetate.
>
Thanks for your comments Steve...
But it will be impossible for methyl propionate to arise from the
reaction of
CH3CH2OH or ethanol and CH3COOH or acetic acid to form methyl
propionate.
That product should emanate from the esterification reaction of
methanol and propionic acid. It is an unlikely product of bread
fermentation.
Although we cannot discount that maybe High Performance Liquid
Chromatography (HPLC)analysis maybe able to isolate that precusors as
well as the product methyl propionate from the dough and bread aroma.
But the main issue here is the formation of the paint thinner smell
which is attributed to ethyl acetate and not methyl propionate.
The actual product is ethyl acetate which unfortunately has similar
molecular formula but the difference will be more obvious in the
structural formula where we can account for the double bond of the
carbonyl in between the methylene CH2 and methoxy OCH3.If we have to
describe it in Nuclear Magnetic Resonance (NMR) analysis data of the
molecule then we should specify that but we are not.
Therefo
I would say that you are absolutely right;IF you had written the
formula clearly with emphasis such as:
CH3CH2C(=O)OCH3 instead of just CH3CH2OC(O)CH3.There you are
emphasizing the presence of the double bond.That is more a rational
molecular formula for methyl propionate then.

Roy