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While going through my book (Organic Chemistry, Paula Bruice) I came across the following line:

We have seen that enantiomers have identical physical properties. They also have identical chemical properties—that is, they react with a given achiral reagent at the same rate. Diastereomers, on the other hand, have different physical properties (meaning different melting points, boiling points, solubilities, specific rotations, and so on) and different chemical properties —that is, they react with a given achiral reagent at different rates.

There seems to be no further explanation about why this is so, and I am unable to figure out the reason behind the difference in physical and chemical properties of diastereomers. I do understand why it would be so in the case of cis-trans isomerism, but not in the case of optical isomers.
What would be a plausible explanation for this?
Any help would be greatly appreciated.

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  • $\begingroup$ Your title and your text say different things. Title "Why do diastereomers have different physical and chemical properties?". Text "I am unable to figure out the reason behind the difference in physical and chemical properties of enantiomers. [...] optical isomers". $\endgroup$
    – user6376297
    Mar 18 at 6:13
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    $\begingroup$ In any case, the answer to the question you are asking in the title is "asymmetry". If you could not tell left from right, you would not be able to distinguish L-tartaric acid from D-tartaric acid. On the other hand, you would be able to distinguish L or D from meso-tartaric acid, e.g. by the fact that in a particular standard drawing of the molecule the two OH groups are on the same side vs on opposite sides. See en.wikipedia.org/wiki/Tartaric_acid. An achiral reagent is like a person who cannot tell left from right. $\endgroup$
    – user6376297
    Mar 18 at 6:21
  • $\begingroup$ @user6376297 thanks, I have corrected the typo in the question, I intended to ask about diastereomers. Your answer was quite helpful, thanks a lot $\endgroup$
    – AG_Coder
    Mar 18 at 9:35

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