Synthesis of β-Hydroxy-α-Amino Acids through an Aldol Condensation

Significance

The authors report an auxiliary-based method for the synthesis of chiral β-­hydroxy-α-acids 4a and 4b. This important product class is a common constituent of peptides and natural products. By utilizing a chiral camphor-based auxiliary, the products are obtained through a diastereoselective aldol reaction. The chiral products 2a,b, 3a and 3b could be obtained in good yields and selectivities with variation of the aldehyde substituent R. Notably, the chiral auxiliary could be recycled without any deterioration of its stereochemical integrity.