[Ak]

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

[azmanam]

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.

[Ak]

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.

[Ak]

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

[azmanam]

I don't see an attachment...

[Ak]

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

[azmanam]

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

[azmanam]

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?

[Ak]

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