[sjb]

What happened to the original poster's question? I don't see many answers to that one!

Well, the last I see on the original part of the thread is just over 13 months old (not counting your revival)

So if the conversion to the product is slow, heat for a longer period of time. Or you can add more of the Wittig reagent. 3.1equiv of MePPh3Br and 3.0equiv of base. And I would order a new bottle of KOtBU. Otherwise, NaH will also do the job.
If prolonged heating is not enough, you can switch to Toluene as solvent. Wittig reagent will work the same as in THF.

Best of luck

[discodermolide]

What happened to the original poster's question? I don't see many answers to that one!

Well, the last I see on the original part of the thread is just over 13 months old (not counting your revival)

I did not revive it, I just tried to answer the question. If you saw the date (which I did not) why did you not lock the thread?

[Borek]

I did not revive it, I just tried to answer the question. If you saw the date (which I did not) why did you not lock the thread?

In general we don't lock old threads. Instead forum displays message:

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

when someone tries to necropost.

What happened to the original poster's question? I don't see many answers to that one!

Well, the last I see on the original part of the thread is just over 13 months old (not counting your revival)

It wasn't discodermolide who revived the thread. Easy to check.

[discodermolide]

I did not revive it, I just tried to answer the question. If you saw the date (which I did not) why did you not lock the thread?

In general we don't lock old threads. Instead forum displays message:

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

when someone tries to necropost.

What happened to the original poster's question? I don't see many answers to that one!

Well, the last I see on the original part of the thread is just over 13 months old (not counting your revival)

It wasn't discodermolide who revived the thread. Easy to check.

I did not see that message:((
Next time I shall examine the dates more closely

[sjb]

What happened to the original poster's question? I don't see many answers to that one!

Well, the last I see on the original part of the thread is just over 13 months old (not counting your revival)

It wasn't discodermolide who revived the thread. Easy to check.

Sorry, I did not mean to imply that discodermolide had revived the original thread, more that the last useful information on the original thread was over 13 months old. Perhaps in hindsight I should have arranged for a splitting of the topic.

[napoleon79]

OK, http://imageshack.us/photo/my-images/827/41653374.jpg/ is what I meant, not necessarily pictures of your apparatus.

Is there a danger that you may be producing the potassium salt of the alcohol, rather than the ylid. Does your reaction mixture change colour after addition of the KOtBu?

After I had given t-BuOk in CH3CN into the bottle (phosphonim salt in CH3CN), This solution changed orange to yellow colour.

And I don't know that what happened is the t-BuOk into phosphonium salt or reverse ? Please you explain it for me understand !

I wanted to create Z isomer more than E isomer by t-BuOK catalyst. Because I wanted to find new method that Z isomer was development it by t-BuOK catalyst. If you have any magazines for wittig reaction, please you will send to me reference.

My lab is very poor because I must do everything that it  had really. I can't buy everything expensive.

I like this forum so people are friendly.

(Edit: emails deleted, don't post the again)

thanks

[Borek]

I did not see that message:((
Next time I shall examine the dates more closely

You couldn't - it was napoleon who necroposted, you were answering a fresh post.

[napoleon79]

The result for wittig reaction with CH3CN solution is light yellow product and has Rf = 0,55 in petro (60:90) : ether.

Some people told me that I need to do with mechanical stirrer. Because stirring bar is weaker than mechanical stirrer. If I do with stirring bar for  t-BuOk and 5-hydroxypentyl phosphonium bromide in THF soluton, this solution won't be yellow or orange colour. Because it is weak, the ylide isn't forming.

please give me some advices

I am very happy and exciting when I discussed with everybody.

thanks

[napoleon79]

If you make the wittig reaction with t-BuOK in THF, then you add LiBr, NaBr, or KBr to investigate the effect. How result is the wittig reaction ? why BuLi can do with n-hexan solution ? Do you do with t-BuOK with n-hexane ? How selective is this reaction with opinions ?

thanks