SN2 Question

[Amber Q]

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Hello All,
I am trying to tackle this SN2 question, and I believe I need some help.
Substrate: 1-Iodo-4-methylhexane (I and Me are on Wedges)
Nuc: -SCH3
Solvent: Acetone

I believe this is an SN2 reaction with no inversion, since there are no stereocenters but the answer to this was SCH3 replaced I (attached on dash) . What am I missing here?

I may be missing something very simple. But it's driving me nuts.

I'd appreciate any help.

 

[Msmouth]

There is a chiral center at substituent 4 methyl and you will have inversion.

 

[ttpharm]

All SN2 have inversion, and the answer has the SCH3 attached by a dash. What's confusing you about that?

 

[Amber Q]

Thanks for your response.
I thought only stereocenters have inversions when they go through SN2.
MSmouth, how is that C-CH3 subtituent attached to 4 different groups.?

 

[Msmouth]

Thanks for your response.
I thought only stereocenters have inversions when they go through SN2.
MSmouth, how is that C-CH3 subtituent attached to 4 different groups.?

The Carbon has a methyl, ethyl, hydrogen, and 3 carbons with the iodine.

 

[Dotoday]

Sn2 is always an inversion. You were right, the first carbon is not a stereocenter, carbon # 4 with methyl, however, you will not have an inversion on the 4th carbon because sn2 does not take place there. They assumed that I is on the dash position, so then sch3 will come and replace it by goal ng to a wedge position. Iodine could have been on the wedge position originally, then sch3 would have came on a dash position. They just assumed one way. Hope this helps.

Sent from my MB855 using Tapatalk

 

[Amber Q]

MSmouth, I see the stereocenter now.
DoToday, SN2 always causes an inversion--GOT IT. I went back on my Chad's notes to verify but I couldn't find it in the notes, I could swear he said inversions are caused by SN2 only if there is a stereocenter where the SN2 is taking place. But I could be wrong. I study at nights while working at an ER so I'm really trying to remember everything. So far I thought I had the Subs reactions and Elimination reactions down but I need to go back to the textbook.
Thank you for all the responses

 

[Msmouth]

Sn2 is always an inversion. You were right, the first carbon is not a stereocenter, carbon # 4 with methyl, however, you will not have an inversion on the 4th carbon because sn2 does not take place there. They assumed that I is on the dash position, so then sch3 will come and replace it by goal ng to a wedge position. Iodine could have been on the wedge position originally, then sch3 would have came on a dash position. They just assumed one way. Hope this helps.

Sent from my MB855 using Tapatalk

Thanks for the really clear explanation. I think I knew that but I didn't remember 100%👍