What are meso compounds?

1 Answer
May 9, 2018

These are formally #RS# compounds....

Explanation:

A meso compound is a symmetric #"RS"# compound with an internal mirror plane, and FORMALLY TWO chiral centres. And this is best appreciated by a simple example .... consider ....

#"H"_3CdotCH(OH)dotCH(OH)CH"_3#

...the dotted carbon are EACH formally chiral...and this compound SHOULD give rise to FOUR diastereomers...#"RR"#, and #"SS"#, and #"RS"#, and #"SR"#.

However, #"RS"#, and #"SR"# CLEARLY have an internal mirror plane, and these are EQUIVALENT meso isomers....and if you cannot see this on paper you should make a model.