10603-03-9

Basic information

• Product Name: 2-Methyl-5-hydroxypentanoic acid lactone
• Synonyms: 2-Methyl-5-hydroxypentanoic acid lactone;Tetrahydro-3-methyl-2H-pyran-2-one;Tetrahydro-3-methylpyran-2-one
• CAS NO: 10603-03-9
• Molecular Formula: C₆H₁₀O₂
• Molecular Weight: 114.16
• Mol File: 10603-03-9.mol
• Article Data: 44

Chemical Properties

• Boiling Point: 153.66°C (rough estimate)
• Flash Point: 79.8°C
• Appearance: /
• Density: 0.9903 (rough estimate)
• Vapor Pressure: 0.145mmHg at 25°C
• Refractive Index: 1.4030 (estimate)
• Storage Temp.: Refrigerator, under inert atmosphere
• Solubility: Chloroform, Methanol (Slightly)
• CAS DataBase Reference: 2-Methyl-5-hydroxypentanoic acid lactone(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Methyl-5-hydroxypentanoic acid lactone(10603-03-9)
• EPA Substance Registry System: 2-Methyl-5-hydroxypentanoic acid lactone(10603-03-9)

Safety Data

• Hazardous Substances Data: 10603-03-9(Hazardous Substances Data)

Usage

General Description

2-Methyl-5-hydroxypentanoic acid lactone, also known as maltol, is a naturally occurring organic compound with a sweet, caramel-like odor. It is commonly found in roasted malt, coffee, cocoa, and bread, and is responsible for the pleasant aroma and flavor of these foods. Maltol is widely used as a flavor enhancer in food, beverages, and tobacco products, and has also been used in the pharmaceutical and cosmetic industries for its fragrance and flavoring properties. It is considered safe for consumption in small quantities and is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration. Maltol is also used in the production of synthetic flavoring agents and as a precursor for the synthesis of pharmaceuticals and agrochemicals.

InChI:InChI=1/C6H10O2/c1-5-3-2-4-8-6(5)7/h5H,2-4H2,1H3

Upstream product

• 64180-78-5 4-bromopent-4-en-1-ol 
• 542-28-9 3,4,5,6-tetrahydro-2H-pyran-2-one 
• 1120-72-5 2-Methylcyclopentanone 
• 26093-63-0 3-methyltetrahydropyran 
• 68258-41-3 3-methylpyran-2-ol 
• 108-18-9 diisopropylamine 
• 74-88-4 methyl iodide 
• 91606-67-6 pent-4-enyl chloroformate 
• 821-09-0 n-Pent-4-enyl alcohol 
• 79964-12-8 2-methyl-acrylic acid but-3-enyl ester 
• 201230-82-2 carbon monoxide 
• 72649-02-6 5,6-dihydro-3-methyl-2H-pyran-2-one 
• 31468-33-4 2-methylglutaric anhydride 
• 107270-41-7 4-(1,3-dithian-2-ylidene)pentan-1-ol 

Downstream Products

• 107174-18-5 3-Methyl-2-phenyl-tetrahydro-pyran-2-ol 
• 4457-71-0 3-methylpentane-1,5-diol 
• 168059-52-7 2-methyl-2-phenylsulfanylpentano-5-lactone 
• 1039455-96-3 C₁₈H₂₈O₄ 
• 107174-25-4 cis-2-phenyl-3-methyltetrahydropyran 
• 152033-08-4 (2S,3S,5R,6S,11R)-3,11-Dimethyl-2-<<<(1,1-dimethylethyl)diphenylsilyl>oxy>methyl>-5-(phenylsulfonyl)-1,7-dioxaspiro<5.5>undecane 
• 153109-02-5 (2S,3S,6R,11R)-3,11-Dimethyl-2-<<<(1,1-dimethylethyl)diphenylsilyl>oxy>methyl>-1,7-dioxaspiro<5.5>undecane 
• 152033-09-5 (δR,2R,5S,6S)-δ,5-Dimethyl-6-<<<(1,1-dimethylethyl)diphenylsilyl>oxy>methyl>tetrahydro-2-pyranylbutanol 
• 1026069-26-0 4-Nitro-benzoic acid (1S,2R,8S,9S,10R)-6-benzenesulfonyl-13-(tert-butyl-diphenyl-silanyloxy)-5-hydroxy-9-methoxymethoxy-2,8,10-trimethyl-1-((S)-3-methyl-pent-4-enyl)-tridecyl ester 
• 152033-16-4 <2S,2(1R),3S,6R,8S,8(3S),9R>-3,9-Dimethyl-2-<1-methyl-4-<<(1,1-dimethylethyl)diphenylsilyl>oxy>butyl>-8-(3-methyl-4-pentenyl)-1,7-dioxaspiro<5.5>undecane 

Relevant articles and documents

Palladium-catalysed Conversion of Alkenols into Five- and Six-membered Ring Lactones at Room Temperature and Atmospheric Pressure

Unsaturated alcohols react with carbon monoxide, oxygen, palladium chloride, copper(II) chloride, and hydrochloric acid in tetrahydrofuran to give lactones in 42-80percent yield.

Nanoflow microreactor for dramatic increase not only in reactivity but also in selectivity: Baeyer-Villiger oxidation by aqueous hydrogen peroxide using lowest concentration of a fluorous lanthanide catalyst

Not only the reaction rate but also the regioselectivity in the scandium bis(perfluorooctanesulfonyl)amide-catalyzed Baeyer-Villiger reaction is remarkably increased by the development of the fluorous nanoflow microreactor system continuously controlled by the nanofeeder DiNaS (Direct Nanoflow System) even in the lowest concentration of the catalyst (?0.1 mol%). The Baeyer-Villiger reaction completes within few seconds as a contact time in the nanoflow microreactor to give the lactone products with high regioselectivity without hydrolysis.

A New Synthesis of Alkylated 2H-Pyran-2-ones and Its Application to the Determination of the Relative and Absolute Configuration of Supellapyrone, Sex Pheromone of the Brownbanded Cockroach, Supella longipalpa

The sex pheromone of the brownbanded cockroach, Supella longipalpa, can be synthesized by direct coupling of a brominated pyrone with an alkylzinc reagent.The stereochemistry of the natural pheromone has been assigned as (2'R,4'R)-5-(2',4'-dimethylheptanyl)-3-methyl-2H-pyran-2-one by a combination of synthesis, chiral gas chromatrography, and electrophysiological measurement.

Isomerisation of ω-hydroxyalkenes under hydroxycarbonylation conditions in palladium catalysed aqueous phase systems

The ω-hydroxyolefins 3-buten-1-ol, 3-buten-1-methyl-1-ol and 4-penten-1-ol were subjected to hydroxycarbonylation conditions in water in the presence of PdCl2(PhCN)2 and 4-8 equiv. of water soluble tris(3-sodiumsulfonatophenyl)phosphine (TPPTS), or N-bis(N′,N′-diethyl-2-aminoethyl)-4-aminomethylphenyl-diphenylphosphine (N3P). Under conditions of high conversion, the olefins primarily undergo isomerisation through a chain walking mechanism with selectivities for aldehyde ranging from 65% to 98%, with the lower values for longer chain alcohols. The lactones formed as the minor product are almost exclusively branched, indicating that in the first step 2,1-insertion is strongly favoured over 1,2-insertion. In the N3P system also linear lactone is produced at lower conversion. Running the reaction in D2O produces multiple deuterium incorporation in all positions of the carbon chain. A mechanism is discussed.

Baeyer-Villiger oxidation of ketones to esters with sodium percarbonate/trifluoroacetic acid

Sodium percarbonate in trifluoroacetic acid has been found to be an effective reagent for the Baeyer-Villiger oxidation of ketones to esters. The scope and limitations of the reaction were explored.

Catalytic oxidation of cyclic ethers to lactones over various titanosilicates

Various crystalline microporous metallosilicates have been used in the liquid phase catalytic oxidation of different cyclic ethers into their corresponding lactones in the presence of dilute aqueous H2O 2 as oxidant. Among the various metallosilicates studied for the oxidation of tetrahydrofuran to γ-butyrolactone, titanosilicates exhibited the best activity than the other metallosilicates such as chromium silicalite-1 (CrS-1), chromium silicalite-2 (CrS-2) and vanadium silicalite-1 (VS-1). The intrinsic activity of TS-1 was found to be marginally higher than the other titanosilicates. Cyclic ethers undergo αC-H oxidation to give the corresponding lactones; whereas open-chain ether produce carboxylic acids by initial αC-H bond oxidation to give ester as an intermediate product, which further undergoes cleavage of -O- linkage to give the final carboxylic acids. The conversion of substituted tetrahydrofuran is decreased with number of -CH3 groups at α- and/or β-position. The lactone formation is hindered when both the α-positions are substituted with methyl substituents. Mechanistically, titanium hydroperoxo complex formed in the titanosilicate/H2O2/H2O system is believed to oxidize the αC-H bond of ethers producing the respective α-hydroxylated product, which undergoes further oxidation to give the lactones (for cyclic ethers) or carboxylic acids (for open-chain ethers).

Biocatalytic Characterization of Human FMO5: Unearthing Baeyer-Villiger Reactions in Humans

Flavin-containing mono-oxygenases are known as potent drug-metabolizing enzymes, providing complementary functions to the well-investigated cytochrome P450 mono-oxygenases. While human FMO isoforms are typically involved in the oxidation of soft nucleophiles, the biocatalytic activity of human FMO5 (along its physiological role) has long remained unexplored. In this study, we demonstrate the atypical in vitro activity of human FMO5 as a Baeyer-Villiger mono-oxygenase on a broad range of substrates, revealing the first example to date of a human protein catalyzing such reactions. The isolated and purified protein was active on diverse carbonyl compounds, whereas soft nucleophiles were mostly non- or poorly reactive. The absence of the typical characteristic sequence motifs sets human FMO5 apart from all characterized Baeyer-Villiger mono-oxygenases so far. These findings open new perspectives in human oxidative metabolism.

Functional divergence between closely related Baeyer-Villiger monooxygenases from Aspergillus flavus

Baeyer-Villiger monooxygenases (BVMOs) catalyse the chemo-, regio- and enantioselective oxidation of ketones to esters and lactones. To date, most of the cloned BVMOs available are derived from bacteria, although Baeyer-Villiger oxidations using fungi have frequently been demonstrated. Here we report the cloning and characterization of four BVMOs from the fungus Aspergillus flavus NRRL3357. Phylogenetic analysis shows these four BVMOs to cluster in a distinct group apart from other well-characterized BVMOs including cyclohexanone, phenylacetone and 4-hydroxyacetophenone monooxygenase. Building on the Grogan classification/clustering of BVMOs, we have designated this new group of BVMOs, Group VI. Group VI BVMOs show an early divergence from the cyclopentanone monooxygenase (CPMO) type BVMOs (Group I). Substrate profiling using cyclic, bicyclic, aliphatic and aryl ketones show a clear divergence in function and specificity not only between this new group of BVMOs and the CPMO-type BVMOs, but also between the four A. flavus BVMO paralogues despite their high sequence similarity. This study not only contributes to the growing number of available BVMOs, but also addresses the current classification of Type I BVMOs, and the usefulness of phylogenetic clustering and prediction of function and selectivity when genome-mining is used to search for new biocatalysts.