N-Carbobenzyloxy-L-valine, commonly abbreviated as Z-Val-OH and identified by CAS 1149-26-4, is a chemically fascinating molecule whose structure dictates its extensive utility, particularly in organic synthesis and pharmaceutical manufacturing. Understanding its core chemical properties and synthesis pathways is key to appreciating its value.

Chemically, N-Carbobenzyloxy-L-valine is an N-protected amino acid. It is derived from L-valine, an essential branched-chain amino acid. The 'carbobenzyloxy' (Cbz or Z) group is attached to the alpha-amino group of L-valine. This Cbz group is a widely used protecting group in peptide chemistry and organic synthesis. Its main function is to render the amine less nucleophilic and basic, thereby preventing unwanted reactions such as self-condensation or undesired acylation/alkylation during synthetic steps. The bulky nature of the Cbz group also influences the conformation of the molecule and can affect the stereochemical outcome of reactions.

The physical properties of Z-Val-OH are also critical for its handling and application. It typically appears as a white to off-white crystalline powder. Its melting point is generally reported in the range of 62-64°C, indicating a relatively stable solid form at room temperature. With a molecular formula of C13H17NO4 and a molecular weight of approximately 251.28 g/mol, its exact composition is well-defined. The compound exhibits solubility in various organic solvents like acetic acid, DMSO, and ethanol, which is advantageous for its use in solution-phase reactions.

The synthesis of N-Carbobenzyloxy-L-valine typically involves the reaction of L-valine with benzyl chloroformate (also known as Cbz-Cl) in the presence of a base. This reaction is a classic example of carbamate formation. Common bases used include sodium carbonate, sodium hydroxide, or potassium carbonate, often in an aqueous or mixed aqueous-organic solvent system. The reaction conditions, such as temperature, pH, and the choice of base and solvent, are carefully controlled to maximize yield and minimize by-product formation. Following the reaction, purification steps such as extraction, washing, and crystallization are employed to obtain the desired high-purity Z-Val-OH.

The strategic placement of the Cbz group is vital. Its stability under a range of reaction conditions, coupled with its selective removal by catalytic hydrogenation (e.g., H2/Pd) or treatment with strong acids (e.g., HBr in acetic acid), makes it a versatile protecting group. This ease of removal after its protective role is fulfilled is a hallmark of effective protecting group strategies in complex organic synthesis.

In summary, the chemistry of N-Carbobenzyloxy-L-valine is centered around the protective functionality of the Cbz group on L-valine. Its well-defined physical properties and the established synthesis pathways make it a reliable and indispensable intermediate for chemists working on intricate molecular constructions, especially within the pharmaceutical industry.