r/s

[recyrb]

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A. R
b. s


i keep getting s??? why or why not?

t butyl is on wedge
​

 

[bharat008]

t-butyl is 1st priority; benzyl is second priority, CH(CH3)2 is third and CH2CH3 is 4th priority.
We need to switch the CH2CH3 with C(CH3)3 so the 4th priority is facing away.
Now do it you will get S but since we made 1 switch; it would be R..

HOpe that helps..

A. R
b. s


i keep getting s??? why or why not?

t butyl is on wedge
​

 

[RCLEE]

I say S. Looking from the bottom up. Looking from bottom up, CH2CH3 is in the back. CH2CH3 = lowest priority. Phenyl group with 1st priority, then (CH3)3, then (CH3)2. Double bond and triple bonds and counted as multiple C-C bonds. It depends on where you place the priority, i guess.

I think phenyl group has the highest priority since it's a tertiary C just like that in t-butyl + additional Carbons.

 

[wired202808]

A. R
b. s


i keep getting s??? why or why not?

t butyl is on wedge
​

I believe it should be the way I numbered it, and since the 4th group is not on a dash you simply cross out 2 and replace it with 4. then you can see its clearly S. I was just doing this based on the first point of difference. Let me know your thoughts.

 

[bharat008]

The reason why i gave the t-butyl first priority compared to benzyl ring is because t-butyl literally has 3 carbons attached while the benzyl has 2 carbons attached for sure but we are assuming that double bond counts twice; that's why it's 3 too..

I read this rule somewhere a while ago. Tried to find the link but couldn't find it..
Could someone make sure abt this??

 

[HannibalLecter]

Yes this is S

Benzyl is obviously first priority because:

Benzyl - C (C,C,C)
T-butyl - C (C,C,C)

You go on to the next carbon and you can determine that the benzyl is first priority over T-butyl because the secondary carbon has more carbons attached to it than T-butyl's methyl group

And, I looked at it as if were at the bottom of the molecule looking straight up and you can see it is S that way