Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Wchase on April 13, 2012, 07:31:46 PM
-
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fi45.photobucket.com%2Falbums%2Ff96%2FBlackFireDragon666%2FHW3.png&hash=9ca69d8a4b2707813a615ac45ec60b7956f08f8f)
"Propose a multistep synthesis for compound X. All Carbon and Nitrogen atoms in X must ultimately derive from the reagents shown in the box. You may use any other reagents that you wish, as long as they do not contribute any carbons or nitrogens to the final product (X). You may temporarily add carbons from another source, such as in a protecting group that gets removed later in the synthesis."
My work so far: I was thinking that starting with reagent 1, to serve as the 6 carbon chain from the carbonyl to the single C-O bond of compound X. Then having the Nitrile (reagent 2) perform a nucleophilic attack on the carbonyl with the lone H, of reagent 1 (and then reduce down the 2 pi bonds of the CN to a single sigma bond). Then substitute the second Carbonyl group with the OH, with the 6 carbon chain of reagent 3 (and then remove the carbonyl group and the OCH2CH3 group). Finally deprotonate the OH of reagent 1 and add on the carbonyl group. (not necessarily all in that order)
Im also not sure if the second carbonyl group of reagent 1 (with the OH) would need to be reduced with something like Zn(Hg) + HCL (with heat)
-
My work so far: I was thinking that starting with reagent 1, to serve as the 6 carbon chain from the carbonyl to the single C-O bond of compound X. Then having the Nitrile (reagent 2) perform a nucleophilic attack on the carbonyl with the lone H, of reagent 1 (and then reduce down the 2 pi bonds of the CN to a single sigma bond). Then substitute the second Carbonyl group with the OH, with the 6 carbon chain of reagent 3 (and then remove the carbonyl group and the OCH2CH3 group). Finally deprotonate the OH of reagent 1 and add on the carbonyl group. (not necessarily all in that order)
Im also not sure if the second carbonyl group of reagent 1 (with the OH) would need to be reduced with something like Zn(Hg) + HCL (with heat)
Let's start with the order. That is a very important aspect, the order. This looks pretty straightforward. Just count the carbons to see which piece is added to which. For example, the acetyl and the ethylamine must come from the acetonitrile, right? You will also need to watch out for any intramolecular reactions as well. I agree the aldehydoacid is the six carbon piece you suggest. I would make it my first reaction to make the long chain.