Question

What is the proper IUPAC name for this molecule?

What is the proper IUPAC name for this molecule? cis-1 -isopropyl-2-methylcycIobutane trans-1 -isopropyl-2-methylcyclobutane (1S, 2R)-1 -isopropyl-2-methylcyclobutane (1R, 2S)-1 -isopropyl-2-methylcycIobutane

Answer 1

SInce both the substituent are different. It can't be cis-trans isomer

R-S:
Give priority to all the 4 bond attached to chiral centre.

To decide R or S
If 4th priority bond is into the plane and 1-2-3 rotate clockwise ---> R
If 4th priority bond is into the plane and 1-2-3 rotate counter clockwise ---> S

If 4th priority bond is Not into the plane and 1-2-3 rotate clockwise ---> S
If 4th priority bond is Not into the plane and 1-2-3 rotate counter clockwise ---> R

carbon number 1 is top

Let us find the configuration on both carbon

Carbon 1 is S carbon 2 is R 2 Answer: C 2 3'1