R S notation

How do we assign R S notation to 3-d molecules??
If we want to convert them to Fischer projection formula then how do we do it??

11 Answers

1
greatvishal swami ·

may i tell the whole method or u want some part of it only

106
Asish Mahapatra ·

whole method to accha hoga

106
Asish Mahapatra ·

take ur time

1
greatvishal swami ·

b4 i start u tell me 1 more thing

u know how to decide the priority of gps attached to C i mean to number them acc to their atomic number(ie about the CIP series )

11
Anirudh Narayanan ·

Can you also please tell how to convert Fischer projection to dash and wedge notation?

1
greatvishal swami ·

ok ani gimme some time

11
Anirudh Narayanan ·

Take ur own time, buddy. [1]

1
greatvishal swami ·

11
Anirudh Narayanan ·

Thanx, Vishal. What about asish's question?

1
greatvishal swami ·

i ansered that bt it got deleted

anyways 1st of all number the 4 gps surrounding the c atom 1,2,3,4 where 1 means gp having highest atomic number
CASE 1: lowest priority gp on verticle axis
now find the rotation while moving from 1-2-3
---------if rotation is cloakwise then its R otherwise S

CASE 2:if lowest priority gp is in horizontal axis
-------------if rotation is clockwise then its S otherwise its R

33
Abhishek Priyam ·

In 3d molecules what U can do is rotate molecule in mind so that lowest priority grp is just opposite to U and then see if its clocksiwe or anti clock wise... then no need for two cases :)

this method is gr8 i myself convert fischer to 3d and then find out R S...

I'll post an image to make it clear if anyone wants....

For converting fischer to dash wedge....

in Vishal's fig U can X,Y,A,B above the plane and the chiral carbons as it is and the one at top and bottom below the plane.....

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