689-00-9

Usage

InChI:InChI=1/C6H8O/c1-3-5-6(7)4-2/h2H,3,5H2,1H3

Upstream product

• 105-31-7 1-hexyn-3-ol 
• 80352-59-6 1-(Trimethylsilyl)-1-hexyn-3-one 
• 100312-93-4 C₆H₇⁽³⁾HO 
• 141-75-3 butyryl chloride 
• 14630-40-1 Bis(trimethylsilyl)ethyne 
• 1066-54-2 trimethylsilylacetylene 
• 693-02-7 hex-1-yne 

Downstream Products

• 1629-60-3 1-hexene-3-one 
• 20964-99-2 1-anilino-hex-1-en-3-one 
• 100518-12-5 hex-1-yn-3-one-(2,4-dinitro-phenylhydrazone) 
• 42426-88-0 1,1-Bis-phenylsulfanyl-hexan-3-one 
• 63390-19-2 β-(p-tolylseleno)butyrylethene 
• 63390-18-1 β-(p-chlorophenylseleno)butyrylethene 
• 58953-13-2 (1E)-1-chlorohex-1-en-3-one 
• 87180-62-9 1c-chloro-hex-1-en-3-one 
• 63390-20-5 β-(phenylseleno)butyrylethene 
• 112247-24-2 2-(Hydroxy-phenyl-methyl)-hex-1-en-3-one 
• 105-31-7 (S)-(-)-1-hexyn-3-ol 
• 105-31-7 (3R)-hex-1-yn-3-ol 
• 105-31-7 1-hexyn-3-ol 

Relevant academic research and scientific papers

Propargylic C[sbnd]H activation using a Cu(II) 2-quinoxalinol salen catalyst and tert-butyl hydroperoxide

The oxidation of alkynes to α,β-acetylenic carbonyls was achieved using only 1 mol% of a Cu(II) 2-quinoxalinol salen catalyst with tert-butyl hydroperoxide. These reactions proceed under mild conditions (70 °C) with excellent selectivity, producing yields up to 78%, and were used on a variety of alkyne substrates to produce the desired corresponding α,β-acetylenic ketones. In addition, these reactions can be run under aqueous conditions using a sulfonated version of the 2-quinoxalinol salen with good yields, reducing the need for volatile organic solvents.

Stereoselective synthesis of pamamycin-607

A macrodiolide antibiotic pamamycin-607 was synthesized by joining two hydroxy acid components. Three cis-2, 5-disubstituted tetrahydrofuran rings in the molecule were stereoselectively prepared by radical cyclization reactions of β-alkoxyvinyl ketone intermediates and a β-alkoxymethacrylate substrate. The key step of the synthesis is characterized by the predominant threo product formation in the radical cyclization reaction of a β-alkoxymethacrylate intermediate.

Enantioselective synthesis of both enantiomers of various propargylic alcohols by use of two oxidoreductases

The oxidoreductases Lactobacillus brevis alcohol dehydrogenase (LBADH) and Candida parapsilosis carbonyl reductase (CPCR) are suitable catalysts for the reduction of ketones to afford enantiopure sec. alcohols. A broad variety of alkynones (1, 3, and 5) are accepted as substrates and the corresponding propargylic alcohols (2, 4, and 6) are obtained in good yield and excellent enantiomeric excess. By changing the steric demand of the substituents the ee values can be adjusted and even the configurations of the products can be altered.

Mutation of cysteine-295 to alanine in secondary alcohol dehydrogenase from thermoanaerobacter ethanolicus affects the enantioselectivity and substrate specificity of ketone reductions

The mutation of Cys-295 to alanine in Thermoanaerobacter ethanolicus secondary alcohol dehycrogenase (SADH) was performed to give C295A SADH, on the basis of molecular modeling studies utilizing the X-ray crystal structure coordinates of the highly homologous T. brockii secondary alcohol dehydrogenase (YKF.PDB). This mutant SADH has activity for 2-propanol comparable to wild-type SADH. However, the C295A mutation was found to cause a significant shift of enantioselectivity toward the (S)-configuration in the reduction of some ethynylketones to the corresponding chiral propargyl alcohols. This result confirms our prediction that Cys-295 is part of a small alkyl group binding pocket whose size determines the binding orientation of ketone substrates, and, hence, the stereochemical configuration of the product alcohol. Furthermore, C295A SADH has much higher actifity towards t-butyl and some α-branched ketones than does wild-type SADH. The C295A mutation does not affect the thioester reductase activity of SADH. The broader substrate specificity and altered stereoselectivity for C295A SADH make it a potentially useful tool for asymmetric reductions. Copyright

Asymmetric reduction of ethynyl ketones and ethynylketoesters by secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus

Secondary alcohol dehydrogenase (SADH) from Thermoanaerobacter ethanolicus, an NADP-dependent, thermostable oxidoreductase, reduces ethynyl ketones and ethynylketoesters enantioselectively to the corresponding propargyl (propargyl = prop-2-ynyl) alcohols. Ethynyl ketones, in general, are reduced with moderate enantioselectivity (with the exception of 4-methylpent-l-yn-3-one, which gives the (S)-alcohol with >98% ee). Although ethynyl ketones bearing a small (up to n-propyl) alkyl substituent are reduced to (S)-alcohols, larger ethynyl ketones give (R)-alcohols. In contrast, ethynylketoesters are converted to (R)-ethynylhydroxyesters of excellent optical purity. Unexpectedly, isopropyl ethynylketoesters give higher chemical yields and higher enantioselectivities of ethynylhydroxyesters than methyl or ethyl ethynylketoesters. The optically pure ethynylhydroxyesters may serve as useful chiral building blocks for asymmetric synthesis.

Reactions of Carbonyl-Conjugated Alkynes with N-Bromosuccinimide and N-Iodosuccinimide in DMF/H2O and Methanol/Sulfuric Acid: Syntheses of Dihalo Diketones, Dihalo Ketoesters, and Dihalo Acetals

The following terminal, carbonyl-conjugated alkynes were reacted with N- bromosuccinimide (NBS) and N-iodosuccinimide (NIS) in MeOH/H2SO4 to give dibromo and diiodo acetals in the indicated yields: 3-butyn-2-one, 1: NBS (75%), NIS (95%); 1-phenyl-1-propyn-l-one, 2: NBS (90%), NIS (40%); 1-hexyn-3-one, 3: NBS (90%), NIS (70%); methyl propiolate, 4: NBS (20%, not isolated), NIS (95%). 4,4-Dimethyl-l-pentyn-3-one (5) gave only a trace of dibromo acetal and no diiodo acetal; tribromide and tetrabromide were the major products. NBS and NIS reactions required, respectively, 20% and 33 wt % of H2SO4. The reaction was unsuccessful with internal alkynes 4-phenyl-3-butyn-2-one and 3-hexyn-2-one which gave only complex mixtures of products. Alkyne 2 gave a significant yield of acetal-ketal in addition to the dihalo acetals. Both the dibromo acetal- ketal and diiodo acetal-ketal were isolated, but only the former could be hydrolyzed to the dibromo acetal. Internal, carbonyl-conjugated alkynes reacted with NBS and NIS in H2O/DMF (40:60) to give the following products in the indicated yields: 4-phenyl-3-butyn-2-one (6): 1-phenyl-3,3- dibromo-1,3-butanedione (17, 70%), 1-phenyl-3,3-diiodo-1,3-butanedione (21, 95%); 3-hexyn-2-one (7): 3,3-dibromo-2,4-hexanedione (18, 80%), 3,3-diiodo-2,4-hexanedione (22, 95%); methyl 3- phenyl-2-propynoate (8): methyl 2,2-dibromo-3-keto-3-phenylpropanoate (19, 43%), methyl 2,2- diiodo-3-keto-3-phenylpropanoate (23, 95%); methyl 2-pentynoate (9): methyl 2,2-dibromo-3- ketopentanoate (20, 80%), methyl 2,2-diiodo-3-ketopentanoate (24, 95%). All reactions, except for 6 and 8 with NBS, required H2-SO4. The terminal, carbonyl-conjugated alkyne, 3-butyn-2-one, did not give products, possibly because of oxidation of the intermediate aldehyde by NBS and NIS. Mechanisms involving electrophilic attack by halogen on the triple bond and an acid-catalyzed mechanism are discussed.

A Pseudomonas sp. Alcohol Dehydrogenase with Broad Substrate Specificity and Unusual Stereospecificity for Organic Synthesis

A new alcohol dehydrogenase from Pseudomonas sp. strian PED has been isolated and characterized.The enzyme exhibits a broad substrate specificity, accepting aromatic, cyclic, and aliphatic compounds as substrates.The Km values were determined as 525 μM for NAD and 75 μM for 2-propanol with a specific activity of 36 U/mg.The kinetic mechanism is ordered bi-bi with the cofactor binding first and releasing last.The enzyme transfers the pro-R hydride of NADH to the si face of carbonyl compounds to yield (R) alcohols.Synthetic-scale reductions of a number of representative compounds were carried out in high enentiomeric excess with in situ regeneration of NADH using 2-propanol as the hydride source and the same enzyme as catalyst.

Rates of Base-Catalyzed Hydrogen Exchange of Terminal Acetylenes in Aqueous Solution. Absence of Resonance Interaction

Rates of detritiation of 13 monosubstituted acetylenes labeled at the acetylenic hydrogen position were measured in aqueous amine buffer solution at 25 deg C, and hydroxide ion catalytic coefficients were evaluated.These rate constants, plus a few additional values from the literature, give a good correlation against inductive or field substituent constants: log(kHO-/M-1s-1) = 1.46+/-0.12 + (8.00+/-0.50)?I.This correlation is not improved by addition of resonance substituted constants, and the coefficients of the resonance term in two different dual parameter (resonance plus field) treatments of the data are in fact zero.

CATALYZED OXIDATION OF ALCOHOLS AND ALDEHYDES WITH IODOSYLBENZENE

RuCl2(PPh3)3 catalyzes oxidation of alcohols to carbonyl compounds by iodosylbenzene and that of aldehydes to carboxylic acids.Catalyzed oxidation of primary alcohols with phenyliodosodiacetate affords aldehydes.