(R)-3-hydroxy-3-methyl-2-oxopentanoate => (S)-2-ethyl-2-hydroxy-3-oxobutanoate
(r)-3-hydroxy-3-methyl-2-oxopentanoate => (s)-2-ethyl-2-hydroxy-3-oxobutanoate
(R)-3-hydroxy-3-methyl-2-oxopentanoate => (S)-2-ethyl-2-hydroxy-3-oxobutanoate
(r)-3-hydroxy-3-methyl-2-oxopentanoate => (s)-2-ethyl-2-hydroxy-3-oxobutanoate