Walden inversion

noun

Wal·​den inversion

ˈwȯldən-

: an inversion of configuration of one optically active compound into another that may or may not lead to a change in the direction of optical rotation and that may be of either of two general types:

a

: inversion involving two reactions in which an optically active compound is changed to another by substitution at its asymmetric center and then regenerated (as dextro-alanine is changed to levo-bromo-propionic acid by nitrosyl bromide and then to levo-alanine by ammonia) but as the optical isomer of the original compound

b

: inversion involving one reaction of an optically active compound at its asymmetric center with resulting configurational change from d to l or vice versa regardless of change in optical rotation (as from levorotatory l-bromo-propionic acid to levorotatory d-alanine by ammonia but not from dextrorotatory l-alanine to levorotatory l-bromo-propionic acid because no inversion of configuration occurs although optical inversion does)

Word History

Etymology

after Paul Walden †1957 Latvian organic chemist

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