[Twickel]

Hi
I am having trouble with the following, there is one more which I will attach soon.

Let me say what I think the answers are and please correct me if I am wrong.

1) Is the second option?

2) I have no idea, im guessing the first step will involve NaOEt though

3) I will post an image

4) nuc armoatic sub, aromatics cant form carbocations to unstable?

[Twickel]

that should be a pentagon and the double bond that got cut should have an Oxygen at the end.

For number2, you need to form an enolate ion, I think


so I believe this is the correct set of steps NaOEt in dry EtOh ii PhCH2Br ii Oh-/h2o/heat iv H+/H2o/heat?

[discodermolide]

For number 2 have you not included an extra C atom in the starting material?
If so then it a hydrogenation of the aromatic ring, if not then I have no idea.

[Dan]

Twickel, can you please spare 30 seconds to proof read your posts before pressing the "post" button? I mean, this is nonsense isn't it?

that should be a pentagon and the double bond that got cut should have an

For number2, you need to form an enolate ion?
I

or NaOEt in dry EtOh ii PhCH2Br ii Oh-/h2o/heat iv H+/H2o/heat?

If you are not willing to put in the effort to ask a coherent question, you should not be too optimistic about coherent responses.

Anyway,

1. As discodermolide asked, check structures for Q1, I think you copied them down incorrectly.

2. Your sequence looks quite good: (i) NaOEt, EtOH; (ii) PhCH₂Br; (iii) NaOH(aq), heat; (iv) H₃O⁺, heat.

You probably won't need step (iii), as the esters will hydrolyse under acidic conditions anyway.

3. Can you redraw/rewrite this question? You ask what the reaction will be when "cyclopentane" is subjected to the conditions - do you really mean cyclopentane? Alkanes will not react with any of the reagents in that sequence. Is the structure you drew in your second post an attempt at the answer or is it the starting material?

4. I agree with your answer.

[Twickel]

I am sorry, I was in a rush, I will be sure to double check my questions. It was meant to be cyclopentanone.

[Dan]

OK, so what is your answer for Q1? Which of those 4 starting materials would you expect to give the product.

For Q3, I don't agree with your answer. Can you draw a mechanism for its formation?

[Twickel]

For Q1 I said it was number 2, because you want the ketone to form the enolate not the aldehyde ( to stop self condensation) option one doesnt form a five membered ring I think ( ihave trouble forming rings).

In regards to Q3, I am unsure as to what role the EtOCO2Et does, is this a claisen condensation that does not go to completion with a Sn2 reaction adding to the enolate formed?

[Twickel]

For Q3 is it one of these? If not I do not know

I think its

[discodermolide]

From your abysmal picture it looks like number 2!

[Twickel]

I am really sorry, my scanner keeps chopping bits of for some reason, I re scanned it three times. Was it number 2 for the cyclopentanone?

Btw, how about the intramolecular aldol condensation, was it the first or second one?

Thanks

[discodermolide]

I am really sorry, my scanner keeps chopping bits of for some reason, I re scanned it three times. Was it number 2 for the cyclopentanone?

Btw, how about the intramolecular aldol condensation, was it the first or second one?

Thanks

Sorry I can't define which reaction you are referring to.

[Twickel]

Sorry for not being specific, in my first image with the first molecule, where I asked what was the starting product of this reaction ( intra molecular aldol condensation)

[Dan]

For Q1 I said it was number 2, because you want the ketone to form the enolate not the aldehyde ( to stop self condensation) option one doesnt form a five membered ring I think ( ihave trouble forming rings).

It is not a choice of 1 or 2 - you posted 4 candidate starting materials in your second posting of this question. Which of those 4 do you think it is - can you draw the mechanism?

For Q3:

You have deprotonated cyclopentanone and jumped straight in with methyl iodide. The first step utilises diethyl carbonate - what do you think that's doing?

[Twickel]

Actually, I can not. How pathetic, I tried but its gone way wrong some where.

I would say its the solvent ( in regards to diethyl carbonate) but going from your tone Im guessing its a reagent.... not too sure sorry

[Twickel]

I think then that its the second option for the intra molecular reaction....