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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: cundi on September 02, 2010, 07:18:03 AM

Title: Allylic alcohol, configuration inversion.
Post by: cundi on September 02, 2010, 07:18:03 AM

Hi guys
Could you suggest me any method for inverting the configuration of an allylic alcohol?

Title: Re: Allylic alcohol, configuration inversion.
Post by: sjb on September 02, 2010, 08:13:12 AM

Do you mean the double-bond geometry? E  :rarrow: Z (or vice versa), or e.g. (4R)-2-pentene-4-ol to (4S)-2-pentene-4-ol?

Title: Re: Allylic alcohol, configuration inversion.
Post by: cundi on September 02, 2010, 10:38:43 AM

Apologies,
I mean R -S configuration.
In my molecule i have not posibily of Z/E isomers; it is a terminal olefin.

See attached pdf

Thanks in advance

Title: Re: Allylic alcohol, configuration inversion.
Post by: sjb on September 02, 2010, 12:55:12 PM

Quote from: cundi on September 02, 2010, 10:38:43 AM

Apologies,
I mean R -S configuration.
In my molecule i have not posibily of Z/E isomers; it is a terminal olefin.

See attached pdf

Thanks in advance

Mitsunobu inversion? http://orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv9p0607 or similar?

Title: Re: Allylic alcohol, configuration inversion.
Post by: OC pro on September 02, 2010, 02:30:33 PM

Mitsunobu on tertiary alcohols is difficult and will not work properly.

Title: Re: Allylic alcohol, configuration inversion.
Post by: cundi on September 03, 2010, 02:46:42 AM

I had already considered mitsunobu reaction! But as OC pro says, it doesn't wotk.

Title: Re: Allylic alcohol, configuration inversion.
Post by: sjb on September 04, 2010, 12:27:46 PM

Hmm, not really sure then - what does happen if you try the Mitsunobu conditions? How did you make the cyclic compound in the first place?