Orgo questions from destroyer

[Bigbirdo]

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1. For question 106, as S become larger, it also become bulkier, which means it becomes a worse nucleophile. Why do we still choose D then? When I see “electronic v.s steric” type of problem, how should I judge?


2. For question 173, why does methylamine have an acidic hydrogen? Isn’t amine a base?

3. For question 179, the answer is B. Is it because Br has a higher priority than methyl, or the lowest number of substituent will be 2?

 

[JDHK]

1. In a protic solvent, the trend for nucleophilicity goes up as you go left and down in the periodic table, so out of all of them sulfer is the best.

2. I'd like an answer to that too (i'm still studying =( )

3. It's because of the lowest number substituent

 

[J777]

Traditionally, it is a base. However, the proton is still ionizable and can be removed in the presence of a sufficiently strong base. Since Grignard reagents are VERY strong bases, they can indeed deprotonate an amine. Also remember that ethers are essentially unreactive unless they are reacted with strong acid such as HBr.