Disclosed are compounds that inhibit proteasomic activity in cells. Also disclosed are pharmaceutical compositions comprising such compounds as well as methods to treat conditions, particularly cell proliferative conditions, such as cancer and inflammatory conditions.
β-hydroxy-α-amino acids is described. Nucleophilic addition of enolates of tricyclic iminolactones 1a and 1b to aldehydes in the presence of 6 equiv of lithium chloride in THF at −78 °C leads to aldol adducts in good yield (63−86%) and high diastereoselectivity (up to >25:1 dr). Subsequently, hydrolysis of the aldol adducts under acidic conditions leads to the corresponding β-hydroxy-α-amino acids in good yields