Author Topic: benzalacetone/benzylidene acetone??
bell
Member posted 01-24-99 12:17 AM
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
I'm not a chemist nor do I claim to be but I've been reading the hive BB for about 3 years and have learned quite alot about chemistry, Still trying to figure out amine, amide, alkayne, alkyine, don't mix this with that ( fire, smoke, cough, cough ) well you know.
Any way I ran across this in a lab manual for organic chemistry by, William Moore and Anthony Winston. It made me have a dream about if this is so close to phenyl acetone should a person even think enough to make it come up in there dreams. I read this in the book,,
since the aromatic aldehyde has no x-hydrogen atoms,it cannot form an enolate ion and thus cannot undergo an aldol condensation by itself. In contrast, the methyl ketone has an alpha hydrogen and can form an enolate ion, :CH2COR. this enolate ion then reacts with the aldehyde rather than with another ketone molecule because the aldehyde carbonyl is far more reactive than the ketone carbonyl. The reaction between the aldehyde and the enolate ion is the rate-determining step; i.e., it controls the overall reaction rate. the subsequent dehydration is favored because the C=C of the x,B-unsaturated ketone that is formed is also conjugated with the aromatic ring, giving a stable extended conjugated system. The product obtained form this reaction depends upon the ratio of benzaldehyde and acetone in the reaction mixture. The condensation of one molecule of benzaldehyde with one molecule of acetone gives benzalacetone, C6H5CH=CHCOCH3(4-phenyl-3butene-2one) also called "benzylidene acetone". With a large excess of acetone, it is possible of obtain benzalacetone in good yield.
Is this something worth dreaming about??
Now this is my first time really posting anything on the hive for discussion, so bee gentle. It beats asking " How do you dream of making?" Hopefully it is a contribution..
read me later
bell
Member posted 02-02-99 04:35 PM
--------------------------------------------------------------------------------
Nothing as far as discussion, I'd hoped this would have gone a little further, will work, won't work, check this or that reference,something 
??
Well I'll keep reading book's and see what else I can Find,
bell
