L-Alanine tert-butyl ester hydrochloride is primarily used in peptide synthesis as a protecting group for the carboxyl function of alanine. It helps in preventing unwanted side reactions during the formation of peptide bonds. The tert-butyl ester group is particularly advantageous because it can be easily removed under mild acidic conditions, making it suitable for sensitive peptide sequences. This compound is also utilized in the preparation of amino acid derivatives and intermediates in organic synthesis, where selective protection of functional groups is required. Its stability and ease of deprotection make it a valuable reagent in both academic research and industrial applications related to peptide chemistry.