R and S configuarations

[issa]

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which has higher priority CHO or CH2OH? according to my big orgo text book CHO has higher priority, but according kaplan blue book CH2OH has more priority. i am confused.

 

[shantster]

which has higher priority CHO or CH2OH? according to my big orgo text book CHO has higher priority, but according kaplan blue book CH2OH has more priority. i am confused.

CHO has more priority since there are two bonds (the double bond) on the O. CH2OH only has one bond on the O.

 

[issa]

CHO has more priority since there are two bonds (the double bond) on the O. CH2OH only has one bond on the O.

yes, this makes sense. i still don't get why CH3 has more priority than CH2CH3.

 

[mlle]

yes, this makes sense. i still don't get why CH3 has more priority than CH2CH3.

it doesn't.

CH3 has lower priority than CH2CH3.

 

[tom_servo_dds]

it doesn't.

CH3 has lower priority than CH2CH3.

I agree with the other posts. You may want to double check your sources against a current text book. Also, for some of these it depends on what else they are connected to (ex. if the CH3 is connected to an O, and if the methylene, CH2, group were connected to a C then it would be higher). The best way to approach these is not to learn a bunch of comparisons, but to learn the rules behind everything and then perform comparisons separately. Hope this helps a bit. By the way, could you please reference where in the Kaplan book it mentions this as well as what version of the book you are using (red, blue, 2007-2008, class review notes). Best of luck to you! 🙂

 

[Chga]

find an organic prof 😛
i agree with the other posts, but just to be on the safe side

 

[Hopin']

which has higher priority CHO or CH2OH? according to my big orgo text book CHO has higher priority, but according kaplan blue book CH2OH has more priority. i am confused.

I agree with other posts... check your source...
When I was studying for my DAT, I found many typos in Kaplan Blue book. Its always better to go with what's in the textbook.

Good Luck