Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Ak on August 07, 2008, 03:42:02 PM
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im working on a synthesis question my prof gave us, and ive been working on it and i keep hitting dead ends. Ive tried retrosynthesis a lot of times but still nothing. I havent given up on it yet but i think i need a prod in the right direction. So if someone can give me a hint it would be greatly appreciated.
And im only allowed to do a given reaction once. And since this is an introduction course i havent learned tht many types of reactions...but i have learned reactions of alcohols, carboxylic acids, carboxylic acid derivatives, ketones, aldehydes, just the basic stuff. Thanks
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Are those really two aldehyde groups?
A product looking like that screams pericyclic reaction to me. But for the life of me I can't find one that makes sense.
Double check that you wrote the problem down correctly? Typically instructors will pick a short synthesis from recent or classic literature. That dialdehyde doesn't even show up in SciFinder, which makes me think something doesn't smell right.
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he gave us the question online and i copied and pasted it directly as it is...he says he always makes up his own questions and never repeats the same ones.
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i took another crack at it today and was able to retrosynthesis it till here (attachment)...now i cant get it from here (attachment) to the original material (see first post). I know it mite seem easy but ive used some reactions already and as ive already said i can only use a give reaction only once. Thanks
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I don't see an attachment...
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lol i forgot to attach it...its now attached and the reactions i have used so far are:
- grignard
- alcohol to aldehyde by LiAlH4
- alcohol to aldehyde by NaBH4
- carboxylic acid to alochol
- nitrile to carboxylic acid
- alkyl halide to nitrile
- ozonolysis to make aldehydes
- H3O for dehydration of alcohol
- NBS to make allyic bromide
- and wittig reaction
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I can get there in 6 steps from the starting material. phenylselenenyl chloride is the key. I won't go into too much more detail because it looks like this is for an assignment.
http://www.sigmaaldrich.com/catalog/search/ProductDetail/ALDRICH/183342
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My 6 steps are not listed in your steps, so that's a good sign.
Do you mean aldehyde to alcohol by reaction with the hydride reagent?
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yeah it is for an assignment thts why ive been trying to do it myself, i just need a little help in the last few steps to get back to the starting material....i cant use your method because i havent learned about phenylselenenyl chloride...and i messed up at a part in my retro synthesis...forget the alcohol to aldehdye it should be:
- alcohol to aldehyde by PCC
- carboxylic acid to ester
- ester to aldehyde
but neways i need some help in the last part i need to know how i can form tht double bond. thanks