nightflight - 8-3-2007 at 06:19
Him
is the carbonyl of an ester some kind of sterically protected, in contrast do a regular ketone or carbonyl?
So is a , say, ketone of a formyl or acetyl-ester protected?
I wouldn´t think so.
[Edited on 8-3-2007 by nightflight]
Sauron - 8-3-2007 at 08:29
Do you mean sterically hindered? Or what exactly do you mean by "protected"?
Aldehydes, ketones, carboxylic acids and esters are all carbonyl compounds. But they have different chemistries because of the structural differences
and especially the different electronic effects of the different substituents: -H for an aldehyde, -R for a ketone, -OH for an acid and -OR for an
ester. Right?
So what do you mean by protected?
nightflight - 8-3-2007 at 10:06
I mean sterically hindered, and as I know that ketones and aldehydes are reactive to some extend, my question is, if a para-substituted aryl compound
with an ester in that position could in general serve as an example for the (non-) reactivity in a certain reaction?
[Edited on 8-3-2007 by nightflight]
solo - 8-3-2007 at 10:23
That certain reaction is quite obscure to know unless you say what you mean.....esters are used in carboxylic acids to protect from reacting while
other groups are being worked on ...while this is true with carboxylic acids it may be necessary to check in the book protective groups to see if in
fact converting a ketone to an ester will help protect that group...........solo
Sauron - 8-3-2007 at 10:29
Okay, draw the structure you have in mind. The ester may or may not be hindered, you haven;t ptovided enough description for anyone to be able to
comment one way or the other.
nightflight - 8-3-2007 at 12:06
Well, Protecting Groups is on my wishlist under most wanted 
Let´s say there´s a halogenbenzene ring with a methylester of the benzoic acid at the para-position, that´s supposed to be coupled at the halide
locus with an alkyl/alkenyl or aryl grignard reagent in a coupling reaction. So I was wondering if A. Fürsters research on iron catalyzed cross
coupling reactions with and arly halide and a Grignard alkyl, or vice versa, a Grignard aryl with an alkyl halide would leave a carbonyl alone.
In fact, I already gave the answere myself, because of the Fe/Grignard complex, the halide-swapping and subsequent coupling reaction proceeds at warp
speed and it was briefly stated, that ketones were tolerated -I was just unsure, because there´s no explicite example given of a ketone, just esters
with the carbonyl.
edit: swapped ketone to carbonyl when in context used with ester.
[Edited on 17-3-2007 by nightflight]
solo - 8-3-2007 at 14:07
wish granted.......solo
http://www.4shared.com/file/11930660/95f7973/Protective_Grou...
Sauron - 8-3-2007 at 17:06
I think you need a book on how to communicate, because people can't read your mind, you know?
Your earlier posts said nothing about PG's just esters
And getting you to narrow this to a p-halogenated methyl benzoate was like pulling teeth. Turns out you had a very narrow question regarding a very
specific transformation, for which you did not ptovide any lit. citation, but you started the thread with a very broadly stated general question which
made little sense because it was so vague and amorphous. Poor show.
Ozone - 8-3-2007 at 17:56
Thanks Solo!
I've been looking around for an affordable print version for some time now. Now I just have to set things up so that i can read .pdf's on the can
.
Thanks again,
O3
nightflight - 9-3-2007 at 02:36
Yes, sorry, I wanted a broad and understandable answere about the reactivity in general of ketone or the carbonyl of an ester.
Thanks solo, for the books´, that was exactly what I needed and yes, communication is as a rule always poor between human beings, and I´m
unfortunately no exception to this issue.
teh all-nighter on the search of this subject left my favorite list in chaos, but FYI I´ve found the
link:http://www.scs.uiuc.edu/chem/gradprogram/chem435/fall04/04_Thompson_Abstract.pdf
[Edited on 9-3-2007 by nightflight]
Sauron - 9-3-2007 at 03:09
I didn't mean to be so gruff, but you were apparently thinking out loud in your original posts and neglecting to give the rest of us the background,
without which it was rather like listening to someone muttering in their sleep.
Glad you found your answers.