[kriggy]

My teacher asked me to try to solve this synthesis (it is not a homework, it is not rated or part of any kind exam. He just asked if I can bring some ideas for it)
its basicly creating the macrocycle with 1 oxygen and 4 nitrogens. This is not that hard, the real problem is creating the dialdehyde which reacts with that pyridine-diethylamine . I came with this:

prot is protecting group protecting the hydroxy group. Im not sure which one I should use. Or if its realy needed. I think yes because then the chloroethanol can form an ether with itself.
I will be thankful for any ideas or corrections.
thanks

[camptzak]

could you be specific? the problem is creating the molecule with two aldehyde groups? why is this a problem?

[kriggy]

That was maybe little bit too much. It is only on paper so I would like to know your oppinions if I didnt miss someting or if something can be done easily. I lack experience in this kind of stuff

[camptzak]

Ok, well what is your protecting group? what are you using to deprotect? this is important.

when you have created your C₄H₈O₃ aldehyde/ether/alcohol molecule, you have it reacting with 2,2 dimethoxyethylamine. It seems as though the carbon with the dimethoxy group could easily act as an electrophile and react with the alcohol creating an ester and releasing methanol, and then the imine could form making a cyclic compound.

You have NaBH₄ being used to reduce and imine, but there is an alcohol functionality on the molecule. I am not 100% on this but couldn't some of the borohydride act as a base and form and alkoxide?

[camptzak]

actually the cyclic ester formation is impossible...disregard that part.

[kriggy]

Ok, well what is your protecting group? what are you using to deprotect? this is important.

I dont know. We didnt cover this in our ochem. I did some research but still dont know which one would be the best. I think acetyl could work but as I said, my knowledge on this topis is very limited.

You have NaBH₄ being used to reduce and imine, but there is an alcohol functionality on the molecule. I am not 100% on this but couldn't some of the borohydride act as a base and form and alkoxide?

Well this is good point. To be honest I never did reduction with NaBH₄ on imine with other funcional group which could react but I think its possible here.
I think I could leave the -OH protected using acetyl group until the reduction of that imine and then imine can be reduced together with acetyl by NaBH₄ which will also reduce the steps by one.

Thank you

EDIT: hm i think acetyl won´t work that way because it will get deprotected by base in 1st step (forming ether) but I think it    doesn´t realy matter. And even if NaBH₄ reacts with that hydroxy group to form alkoxide, it should be hydrolyzed back to alkohol by acid in next step. It might cause some troubles with separation of the product.

[orgopete]

I would do more lit searching. I suspect there is relevant chemistry already published.

Two things I am concerned with are intramolecular reactions and the basic amine. I've not done an oxidation of an alcohol with a secondary amine, but does anyone else think the amine can react with the oxidant?