DIR Return Create A Forum - Home
---------------------------------------------------------
Chemistry:The Central Science
HTML https://kolathechemist.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: General Organic Chemistry
*****************************************************
#Post#: 1254--------------------------------------------------
Urgent help needed!
DIR By: Chris
Date: November 27, 2012, 11:20 am
---------------------------------------------------------
Please How to prepare 1-phenylbutenone from acetophenone
Reagents, mechanism needed.! Urgent
thanks
#Post#: 1268--------------------------------------------------
Re: Urgent help needed!
DIR By: Michel
Date: November 27, 2012, 1:54 pm
---------------------------------------------------------
What is the position of the double bond in the phenylbutenone?
#Post#: 2203--------------------------------------------------
Re: Urgent help needed!
DIR By: Potla
Date: February 26, 2013, 5:35 am
---------------------------------------------------------
If you mean the following compound:
Ph-CO-CH=CH-CH3,
Then this is a crossed aldol, and can be prepared by crossing
PHCOCH3 with CH3CHO in presence of a base like NaOEt.
The other position of the pi-bond would require a different
method, you can use Br2/AcOH on acetophenone to get PhCOCH2Br,
which can then be converted to a grignard, and then you can
attack a mole of CH3CHO followed by Anti-Sayetzeff's dehydration
using bulky bases like Na-t-Butoxide.
I think the second process will have a higher yield, but it
requires more steps.
You can also change the position of the pi bond in
Ph-CO-CH=CH-CH3 using our old bulky base after HBr-addition.
Hope that helps. :)
*****************************************************
Page 1 of 1