How is (3S)-3-Amino-4-[(2-methyl-2-propanyl)oxy]-4-oxobutanoic acid (CAS: 4125-93-3) typically synthesized?

(3S)-3-Amino-4-[(2-methyl-2-propanyl)oxy]-4-oxobutanoic acid is synthesized through a multi-step process involving the protection of the amino group, introduction of the oxybutyl moiety, and subsequent removal of the protecting group. Commonly, the synthesis involves protecting the amino group with a trifluoroacetyl (TFA) or an acetyl group, followed by the introduction of the oxybutyl moiety via a SnAr reaction. The protecting group is then removed to yield the final product.