L-(+)-Prolinol
[CAS# 23356-96-9]

Identification

• Classification: Biochemical >> Amino acids and their derivatives >> Amino alcohol derivative
• Name: L-(+)-Prolinol
• Synonyms: (S)-(+)-2-Pyrrolidinemethanol; S-2-Hydroxymethyl-pyrrolidine
• Molecular Formula: C₅H₁₁NO
• Molecular Weight: 101.15
• Protein Sequence: P
• CAS Registry Number: 23356-96-9
• EC Number: 245-605-2
• SMILES: C1C[C@H](NC1)CO

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*, 1.025 g/mL (Expl.)
• Melting point: 42 - 44 °C (Expl.)
• Boiling point: 211.0 °C 760 mmHg (Calc.)^*, 269.9 °C (Expl.)
• Flash point: 86.1 °C (Calc.)^*, 86 °C (Expl.)
• Index of refraction: 1.455 (Calc.)^*, 1.485 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318

Discovery and Applications

L-(+)-Prolinol is a chiral amino alcohol derived from the naturally occurring amino acid L-proline. Its molecular formula is C₅H₁₁NO, and it features a pyrrolidine ring bearing a hydroxymethyl group at the position corresponding to the carboxyl carbon of proline, resulting in an alcohol functional group in place of the carboxylic acid.

This compound is notable for its use as a versatile chiral building block and ligand in asymmetric synthesis. The presence of both an amine and an alcohol functional group allows for multiple modes of coordination to metal centers, making L-(+)-prolinol an important ligand for enantioselective catalysis. It has been employed in the development of catalysts for asymmetric reactions such as hydrogenation, epoxidation, and allylation.

L-(+)-Prolinol can be synthesized by reduction of L-proline using reagents such as borane or lithium aluminum hydride. The stereochemistry is retained during this transformation, preserving the L-configuration and resulting in an optically active molecule that rotates plane-polarized light in the positive direction, as indicated by the (+) sign.

The compound’s chiral pyrrolidine ring provides rigidity and well-defined stereochemistry, which are beneficial for inducing asymmetry in catalytic processes. Its ability to act as a bidentate ligand through the nitrogen and oxygen atoms enhances its coordination properties with transition metals.

In addition to catalysis, L-(+)-prolinol is used in the synthesis of chiral auxiliaries, organocatalysts, and pharmaceuticals. Its derivatives serve as intermediates in the preparation of more complex molecules with specific stereochemical requirements.

Physically, L-(+)-prolinol is typically a colorless to pale yellow liquid or crystalline solid. It is soluble in water and many organic solvents due to the polar amine and alcohol groups. Analytical techniques such as NMR, IR, and optical rotation measurements are commonly used to characterize its purity and stereochemical integrity.

In summary, L-(+)-prolinol is a chiral amino alcohol derived from L-proline, widely utilized in asymmetric synthesis as a chiral ligand and building block. Its stereochemical purity and functional versatility make it a valuable compound in organic and pharmaceutical chemistry.

References

2020. Catalytic Processes for Biomass-Derived Platform Molecules Valorisation. Topics in Catalysis, 63(15-16).
DOI: 10.1007/s11244-020-01309-9

2021. Asymmetric Synthesis of P-Stereogenic Secondary Phosphine Oxides (SPOs). Synthesis, 53(20).
DOI: 10.1055/a-1582-0169

2022. Chemoselective and Enantioselective Fluorescent Recognition of Prolinol. The Journal of Organic Chemistry, 87(21).
DOI: 10.1021/acs.joc.2c02152