# Steroisomerism in cyclic compounds [closed]

What about stereochemistry of 1,2,3,4-tetrahdroxy cyclobutane How will we decide the stereocentre it's eating me can anybody help.

## closed as off-topic by Todd Minehardt, Zhe, Klaus-Dieter Warzecha, Jon Custer, bonMar 12 '17 at 18:02

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• – Loong Mar 12 '17 at 8:40

In the RULES FOR THE NOMENCLATURE OF ORGANIC CHEMISTRY SECTION E: STEREOCHEMISTRY, published in Pure Appl. Chem., 1976, 45, 11-30, you find:

E—2.3.3. When one substituent and one hydrogen atom are attached at each of more than two positions of a monocycle, the steric relations of the substituents are expressed by adding r (for reference substituent), followed by a hyphen, before the locant of the lowestnumbered of these substituents and c or t (as appropriate), followed by a hyphen, before the locants of the other substituents to express their relation to the reference substituent.

This means: pick one centre as a reference (r-1) and express the relative stereochemistry of the other centres, that is the relative orientation of the $\ce{OH}$ groups with respect to the reference, using c (if the substituent is on the same face of the ring) or t (if the substituent is on the opposite face of the ring).

From what i see...at a basic point of view...there is no carbon with 4 different functional groups...hence i guess its optically inactive...as in each carbon is bonded to 2 identical carbons which are further bonded to the same carbon ...so the functional group dosent matter...Hopefully thats it

• But it has 4 stereoisomers – user41111 Mar 12 '17 at 8:15

To solve this first we number the carbons as

Now when we consider cis form of 1 and 2 carbon there will be two stereoisomers cis and trans for 3 and 4 carbon

Now when we consider trans form of 1 and 2 carbon there will be two stereoisomers cis and trans for 3 and 4 carbon

Hence total 4 stereoisomers