Levorotation (also spelled laevorotation) is the counterclockwise rotation of plane polarized light.

The rotation of interest in chemistry is induced by a chiral molecule. Note that the direction of rotation cannot be predicted from the R or S designation of the configuration at a stereocenter: in some cases the R isomer is dextrorotatory and the S isomer is levorotatory, while in other cases it is the other way around. Also, the direction of rotation can change with the wavelength of the light.

Notes

1. The first word component levo- comes from Latin word for “on the left side”.

polarization | stereochemistry

Lévogyre