Cryptochirality

Cryptochirality in stereochemistry is a special case of chirality where due to the electronic properties of the chiral molecule its specific rotation is non-measurable. The term was introduced by K. Mislow in 1977.

For example the alkane 5-ethyl-5-propylundecane found in certain species of Phaseolus vulgaris has two enantiomeric forms without any observable optical rotation: