Attacking epoxides

[woox]

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Question on epoxide attacking. If it is ACIDIC conditions, the nucleophile attacks @ most sub. carbon. If it is BASIC conditions, the nucleophile attack least sub. carbon.

However if the nucleophile is a Gringard, or LiX or alkyene (made with NaNH2) then it always attacks at least sub carbon on epoxide, regardless of Acid/Base conditions....

Correct?

 

[LaughingGas]

Question on epoxide attacking. If it is ACIDIC conditions, the nucleophile attacks @ most sub. carbon. If it is BASIC conditions, the nucleophile attack least sub. carbon.

However if the nucleophile is a Gringard, or LiX or alkyene (made with NaNH2) then it always attacks at least sub carbon on epoxide, regardless of Acid/Base conditions....

Correct?

Semiright. Gridnard, Organometallics and others u mentioned, you need them to be in BASIC solution(i.e. Grignard in acid is no longer a grignard). so when you use those with epoxides, you automatically have to think you are doing it in a basic solution. So yes you are correct that attacks the least substituted, but its not regardless of acid/base condition.

I think.......

 

[JustwantDDS]

Semiright. Gridnard, Organometallics and others u mentioned, you need them to be in BASIC solution(i.e. Grignard in acid is no longer a grignard). so when you use those with epoxides, you automatically have to think you are doing it in a basic solution. So yes you are correct that attacks the least substituted, but its not regardless of acid/base condition.

I think.......

yesss acid workup is AFTER the attack
grignard in acid= messes up the grignard so....