Organic Chemistry Synthesis Help!

[znny23]

Hello,

 

I need help synthesizing 3-methyl-but-1-ene and 2,3dimethylbutane using only ethanol as my organic starting material. Methyl-iodide can be used an also any other inorganic reagent or organic solvent. Keep in mind please that I am only in orgo2 and have not gotten past diels alder reactions.

I want to see if my proposed solution makes sense.

 

My proposed for 3-methyl-but-1-ene

 

I was thinking of using SOCL2 in pyridine to get chloroethyl and then use a gilman reagent to add on ch2ch3 resulting in a butane. Than use br2 with UV to get a 2-bromobutane and then use gilman reagent to get 2 methylbutane. From here I am stuck. Maybe i did something wrong?

 

For the 2nd one. I am completely lost maybe telling me where to start off will help. Thank you very much!

[Horza2002]

First of all, this seems to be rather a hard problem given your lack of carbon based units!

 

For 3-methyl-but-1-ene, start from ethanol think mild oxidations, grignard reactions, enolate reactions, oxidations and eliminations.

 

For 2,3-dimethylbutane i have come up with a route to do. Starting from ethanol think mild (HINT!) oxidation reactions, enolate reactions and grignard reactions.

[znny23]

nvm for the first one i think i got it . Use socl2 and pyridine to get chloroethane than gilamn reagent to get butane than uv brominate than strong base to elminate and then NBS/dmso to allyic brominate and then gilman one more time ?

 

Edit: uv bromination wont work cuz zaitsev product will form nvm.

Edited March 6, 2011 by znny23

[Horza2002]

Ok...erm, let me have a think about this then...if you haven't learnt about those simple topics yet, then this problem has just got a lot harder. By the sounds of it, you are just starting at chemistry...so it might be that you are expected to use chemical reactions that are taught to you at the begininning but never use because they are totally useless.

[znny23]

Ok...erm, let me have a think about this then...if you haven't learnt about those simple topics yet, then this problem has just got a lot harder. By the sounds of it, you are just starting at chemistry...so it might be that you are expected to use chemical reactions that are taught to you at the begininning but never use because they are totally useless.

 

Lol yes let me give it one more try. once u from Butane u can UV brominate to get 2-bromo butane than elminate using a strong base to get 2-butene. Than use NBS and DMSO to get allyic bromination yieldint 1-bromo-2-butene. Than use H2 and catalyst. to get 1 bromo butane. Than elminate to get 1-butene. Use dmso and nbs to get 3-bromo-1-butene. Than finish it off with a gilman reagent and adda methyl. lol