1-Methylcyclopentanol

Synthetic Routes and Reaction Conditions: 1-Methylcyclopentanol can be synthesized through the hydration of 1-methylcyclopentene. This process involves the addition of water to the double bond of 1-methylcyclopentene, typically using an acid catalyst such as sulfuric acid. The reaction conditions generally include a controlled temperature and pressure to ensure the efficient conversion of the alkene to the alcohol.

Industrial Production Methods: In an industrial setting, this compound is produced by catalytic hydrogenation of 1-methylcyclopentanone. This method involves the reduction of the ketone group to a hydroxyl group using hydrogen gas in the presence of a metal catalyst such as palladium or platinum. The process is carried out under high pressure and moderate temperature to achieve high yields.

Types of Reactions: 1-Methylcyclopentanol undergoes various chemical reactions, including:

Oxidation: It can be oxidized to 1-methylcyclopentanone using oxidizing agents like potassium permanganate or chromium trioxide.

Reduction: The compound can be reduced to 1-methylcyclopentane using reducing agents such as lithium aluminum hydride.

Substitution: It can participate in nucleophilic substitution reactions where the hydroxyl group is replaced by other functional groups.

Common Reagents and Conditions:

Oxidation: Potassium permanganate (KMnO4) in an acidic medium.

Reduction: Lithium aluminum hydride (LiAlH4) in anhydrous ether.

Substitution: Hydrochloric acid (HCl) or sulfuric acid (H2SO4) for converting the hydroxyl group to a better leaving group.

Major Products:

Oxidation: 1-Methylcyclopentanone.

Reduction: 1-Methylcyclopentane.

Substitution: Various substituted cyclopentane derivatives depending on the nucleophile used.

Pharmaceutical Synthesis

1-Methylcyclopentanol is primarily utilized as a reagent in the synthesis of bioactive compounds. Notably, it plays a crucial role in the preparation of cis-2,5-dicyanopyrrolidine inhibitors of dipeptidyl peptidase IV, which are significant in the treatment of type 2 diabetes . Additionally, it is involved in the synthesis of Lomifylline, a methylxanthine analog that induces calcium release from intracellular stores via the ryanodine receptor, highlighting its potential therapeutic applications .

Photoresist Materials

Another notable application of this compound is in the production of photoresist materials used in semiconductor manufacturing. The compound can be converted into this compound-acrylate, which serves as a critical component in high-resolution photoresists for integrated circuit production. These materials undergo changes in solubility upon exposure to radiation, making them essential for photolithography processes .

Data Table: Applications and Properties

Case Study 1: Inhibition of Dipeptidyl Peptidase IV

A study published in Tetrahedron Letters discusses the synthesis of cis-2,5-dicyanopyrrolidine derivatives using this compound as a key reagent. The resulting compounds exhibited significant inhibitory activity against dipeptidyl peptidase IV, demonstrating their potential as therapeutic agents for managing blood glucose levels .

Case Study 2: Development of Photoresist Materials

Research on the synthesis and application of this compound-acrylate highlights its effectiveness as a photoresist material. The study indicates that this compound enhances the resolution and performance of photoresists used in semiconductor fabrication processes, addressing challenges associated with traditional materials .

The mechanism of action of 1-Methylcyclopentanol involves its interaction with various molecular targets and pathways. For instance, in oxidation reactions, the hydroxyl group is converted to a carbonyl group through the transfer of electrons and protons. In reduction reactions, the hydroxyl group is replaced by a hydrogen atom through the addition of electrons and protons. These reactions are facilitated by specific enzymes or catalysts that lower the activation energy and increase the reaction rate.

Physical Properties

The physical properties of 1-methylcyclopentanol are influenced by its cyclic structure and tertiary alcohol functionality. Below is a comparative analysis with structurally related alcohols:

Key Observations :

• Boiling Points: Increasing ring size (cyclopentane → cycloheptane) correlates with higher molecular weight and boiling points. However, this compound has a slightly lower boiling point than cyclopentanol due to reduced hydrogen bonding in tertiary alcohols .
• Solubility: Tertiary alcohols like this compound are less water-soluble than primary or secondary alcohols (e.g., cyclopentanol) due to reduced polarity and increased hydrophobic surface area .

Chemical Reactivity

This compound’s reactivity is governed by its tertiary alcohol structure, which stabilizes carbocation intermediates in substitution reactions.

Comparative Insights :

• Dehydrative Coupling: this compound reacts with benzenethiol in the presence of triflic acid to form sulfides, a reaction less efficient in smaller-ring analogs like cyclopentanol .
• Thermodynamic Stability : Enthalpy of formation (ΔfH°) is -343.3 kJ·mol⁻¹ in the liquid state, comparable to other cyclic alcohols but lower than linear analogs due to ring strain .

1-Methylcyclopentanol is an organic compound classified as a secondary alcohol, characterized by its molecular formula $C_6H_{12}O$ and a molecular weight of $100.16\,g/mol$ . Its structure consists of a cyclopentane ring with a methyl group and a hydroxyl group, which contribute to its unique chemical properties and potential biological activities. This article explores the biological activity of this compound, focusing on its antimicrobial properties, mechanisms of action, and relevant case studies.

• Molecular Formula: $C_6H_{12}O$
• Molecular Weight: $100.16\,g/mol$
• Classification: Secondary alcohol
• Appearance: White to almost white powder .

The mechanism by which this compound exerts its biological effects is likely linked to its ability to form hydrogen bonds and interact with various enzymes and receptors due to its hydroxyl group. This interaction can modulate biological processes, potentially influencing metabolic pathways or acting as a solvent for various biomolecules .

Study on Antimicrobial Activity

A study investigating the antimicrobial effects of various alcohols found that secondary alcohols, including compounds similar to this compound, significantly inhibited the growth of both gram-positive and gram-negative bacteria. The study highlighted that the presence of the hydroxyl group is crucial for enhancing membrane permeability and disrupting microbial integrity .

Synthesis and Application in Drug Development

Research has shown that this compound can serve as an intermediate in the synthesis of complex organic molecules and pharmaceuticals. Its unique structure allows for further functionalization, which is valuable in medicinal chemistry for developing new therapeutic agents .

Comparative Analysis

To better understand the biological activity of this compound in relation to other compounds, a comparative analysis is presented below:

Basic Research Questions

Q. What are the common synthesis routes for 1-Methylcyclopentanol, and how can their yields be optimized experimentally?

• Methodological Answer : The two primary synthesis routes include:

• Hydration of 1-Methylcyclopentene : This method yields ~38% under standard conditions. Optimization may involve adjusting reaction temperature, catalyst selection (e.g., acid catalysis), and solvent polarity .
• Grignard Reaction : Reacting methylcyclopentane with isobutyric acid derivatives. Yield improvements require rigorous control of reactant stoichiometry and reaction time .
  • Characterization : Post-synthesis, confirm purity via gas chromatography (GC) and structural identity using $^1 \text{H NMR}$ (e.g., methyl group resonance at δ ~1.2 ppm and hydroxyl proton at δ ~1.5 ppm) .

Q. What are the key physicochemical properties of this compound, and how are they experimentally determined?

• Methodological Answer :

• Boiling Point : 135–136°C (determined via distillation under reduced pressure) .
• Melting Point : 36–37°C (measured using differential scanning calorimetry) .
• Density : 0.904 g/mL at 25°C (pycnometer or digital densitometer) .
• Safety : Flash point = 41°C (Pensky-Martens closed-cup tester); handle in well-ventilated areas due to flammability (R11) and toxicity (R22, R41) .

Q. What standard analytical techniques are used to verify the identity and purity of this compound?

• Methodological Answer :

• Chromatography : GC-MS for purity assessment (retention time comparison with standards) .
• Spectroscopy : $^1 \text{H NMR}$, $^{13} \text{C NMR}$, and IR (e.g., O-H stretch at ~3300 cm$^{-1}$) for structural confirmation .
• Elemental Analysis : Validate molecular formula (C$_6$H$_{12}$O) via combustion analysis .

Advanced Research Questions

Q. How do structural features of this compound influence its reactivity in nucleophilic substitution reactions (e.g., with concentrated HBr)?

• Methodological Answer :

• Mechanistic Analysis : The methyl group at the 1-position creates steric hindrance, slowing S$_N$2 reactions. Reactivity comparisons with ethanol or 2-methylcyclopentanol require kinetic studies (e.g., monitoring reaction rates via $^1 \text{H NMR}$) .
• Experimental Design : Use controlled conditions (temperature, solvent polarity) to isolate steric vs. electronic effects. Compare activation energies via Arrhenius plots .

Q. How can researchers resolve discrepancies in reported thermodynamic data (e.g., heat capacity) for this compound?

• Methodological Answer :

• Systematic Review : Follow Cochrane guidelines to evaluate data sources, methodologies (e.g., calorimetry techniques), and sample purity (e.g., chromatographic validation) .
• Reanalysis : Reproduce experiments using adiabatic calorimetry (e.g., discrepancies in 1996KAB/BLO vs. 2007STR/VAN studies may arise from impurities or instrumentation differences) .

Q. What strategies are effective for optimizing low-yield synthesis routes (e.g., 38% yield in 1-Methylcyclopentene hydration)?

• Methodological Answer :

• Catalyst Screening : Test Brønsted/Lewis acids (e.g., H$_2$SO$_4$, BF$_3$) to improve reaction efficiency .
• Solvent Effects : Explore polar aprotic solvents (e.g., DMF) to stabilize transition states.
• In Situ Monitoring : Use FTIR or Raman spectroscopy to track intermediate formation and adjust reaction parameters dynamically .

Q. How does the methyl group in this compound affect its intermolecular forces and solubility in aqueous vs. nonpolar solvents?

• Methodological Answer :

• Solubility Studies : Measure partition coefficients (log P) via shake-flask method. The methyl group increases hydrophobicity, reducing water solubility compared to unsubstituted cyclopentanol .
• Computational Modeling : Use molecular dynamics simulations (e.g., AMBER force field) to model hydrogen-bonding interactions and predict solubility trends .