1679-55-6

Upstream product

• 2938-48-9 3,3-dimethyl glutaric acid anhydride 
• 681-57-2 2,2-dimethylglutaric acid 
• 3121-82-2 2,2-dimethylpentane-1,5-diol 

Downstream Products

• 27143-31-3 2,2,7,7-tetramethyloctane-1,8-diol 

Relevant academic research and scientific papers

(Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2- A nd 5-positions, [2,5-(SiMe3)2-3,4-(CH2)4(δ4-C4C= O)]Fe(CO)3 (1) and [2,5-(SiMe3)2-3,4-(CH2)3(δ4-C4C= O)]Fe(CO)3 (2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two primary alcohols occurred with catalyst 1, but selectivity was low based on alcohol electronics and modest based on alcohol sterics. Evidence for a transfer dehydrogenation mechanism was found, and insight into the origin of selectivity in the lactonization of 1°/2° diols was obtained. Additionally, spectroscopic evidence for a trimethylamine-ligated iron species formed in solution during the reaction was discovered.

Toward Orally Absorbed Prodrugs of the Antibiotic Aztreonam. Design of Novel Prodrugs of Sulfate Containing Drugs. Part 2

Aztreonam, first discovered in 1980, is an FDA approved, intravenous, monocyclic beta-lactam antibiotic. Aztreonam is active against Gram-negative bacteria and is still used today. The oral bioavailability of aztreonam in humans is less than 1%. Herein we describe the design and synthesis of potential oral prodrugs of aztreonam.

Efficient and Selective Cu/Nitroxyl-Catalyzed Methods for Aerobic Oxidative Lactonization of Diols

Cu/nitroxyl catalysts have been identified that promote highly efficient and selective aerobic oxidative lactonization of diols under mild reaction conditions using ambient air as the oxidant. The chemo- and regioselectivity of the reaction may be tuned by changing the identity of the nitroxyl cocatalyst. A Cu/ABNO catalyst system (ABNO = 9-azabicyclo[3.3.1]nonan-N-oxyl) shows excellent reactivity with symmetrical diols and hindered unsymmetrical diols, whereas a Cu/TEMPO catalyst system (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl) displays excellent chemo- and regioselectivity for the oxidation of less hindered unsymmetrical diols. These catalyst systems are compatible with all classes of alcohols (benzylic, allylic, aliphatic), mediate efficient lactonization of 1,4-, 1,5-, and some 1,6-diols, and tolerate diverse functional groups, including alkenes, heterocycles, and other heteroatom-containing groups.

Highly practical copper(I)/TEMPO catalyst system for chemoselective aerobic oxidation of primary alcohols

Aerobic oxidation reactions have been the focus of considerable attention, but their use in mainstream organic chemistry has been constrained by limitations in their synthetic scope and by practical factors, such as the use of pure O2 as the oxidant or complex catalyst synthesis. Here, we report a new (bpy)CuI/TEMPO catalyst system that enables efficient and selective aerobic oxidation of a broad range of primary alcohols, including allylic, benzylic, and aliphatic derivatives, to the corresponding aldehydes using readily available reagents, at room temperature with ambient air as the oxidant. The catalyst system is compatible with a wide range of functional groups and the high selectivity for 1° alcohols enables selective oxidation of diols that lack protecting groups.

Mild and chemoselective synthesis of lactones from diols using a novel metal-ligand bifunctional catalyst.

[reaction: see text] A novel amino alcohol-based Ir bifunctional complex acts as an efficient catalyst for oxidative lactonization of 1,4- or 1,5-diols with a substrate-to-catalyst molar ratio of 200-1000 in acetone or butanone. The reaction proceeds with broad functional group tolerance to give lactone in high yield at room temperature. The catalyst precursor Cp*IrCl[OCH(2)C(C(6)H(5))(2)NH(2)] is isolated and characterized by a single-crystal X-ray analysis.

Pd(II)-hydrotalcite-catalyzed selective oxidation of alcohols using molecular oxygen

A novel heterogenized Pd catalyst, Pd supported by hydrotalcite [Pd(II)-hydrotalcite], was synthesized by a simple operation from commercially available hydrotalcite, Pd(OAc)2 and pyridine. The catalyst was effective for the oxidation of a wide range of alcohols using molecular oxygen as a sole oxidant. With this catalytic system, various alcohols were readily converted to the corresponding aldehydes or ketones selectively in high to excellent yields. Sterically less hindered substrates were converted to the corresponding ketones much faster than the hindered ones. For example, cyclohexanol was converted to cyclohexanone in 79% yield for 15 hr, while larger-sized cyclic alcohols were oxidized to the corresponding ketones only in 32-77% yields in the same reaction time. The catalyst was also applicable to the oxidation of unsaturated alcohols such as geraniol and nerol without any isomerization of an alkenic part. Modified Pd(II)-hydrotalcite [Pd(II)-hydrotalcite(m)] could be reused several times while keeping its activity.

Palladium(II)-catalyzed oxidation of alcohols to aldehydes and ketones by molecular oxygen

A novel combination of Pd(OAc)2/pyridine/MS3A catalyzes the aerobic oxidation in toluene of a variety of primary and secondary alcohols into the corresponding aldehydes and ketones in high yields. Various substituents and protecting groups are compatible with this oxidation. The ca. 2:3 ratio of O2 uptake to product yield is observed, whereas in the absence of MS3A, the ratio is ca. 1:1, suggesting the in situ formation of H2O2 and its decomposition by MS3A into water and oxygen. A catalytic cycle including the formation of a Pd(II)-alcoholate followed by β-elimination of a Pd(II)H species and a carbonyl compound and then the formation of a Pd(II)OOH species is proposed.

Synthesis of lactones via the oxidation of α,ω-diols with sodium bromite and alumina under water free conditions

Oxidation of α,ω-diols with sodium bromite can be readily performed in dichloromethane to afford lactones in fair good yield under mild and neutral conditions with the aid of chromatographic acidic alumina.

Ruthenium Complex Catalyzed Regioselective Dehydrogenation of Unsymmetrical α,ω-Diols

Ruthenium complex catalyzed regioselective dehydrogenation of unsymmetrically substituted 1,4- and 1,5-diols in the presence of such a hydrogen acceptor as α,β-unsaturated ketone gave predominantly β-substituted γ-lactones and γ-substituted δ-lactones, respectively.Among the ruthenium complexes, RuH2(PPh3)4 was the most active and selective catalyst and showed high catalytic activity even at 20 deg C.For example, 2,2-dimethyl-1,4-butanediol was quantitatively converted to dihydro-4,4-dimethyl-2(3H)-furanone and dihydro-3,3-dimethyl-2(3H)-furanone in a ratio of 99.6/0.4 in the presence of 4-phenyl-3-buten-2-one (hydrogen acceptor) and a catalytic amount of RuH2(PPh3)4 at 20 deg C.The proposed main factor controlling the regioselectivity is the steric constraints produced by the substituent(s) of a diol at the coordination step of alkoxy group to ruthenium.

Regioselective Hydrogenation of Unsymmetrically Substituted Cyclic Anhydrides Catalyzed by Ruthenium Complexes with Phosphine Ligands

Regioselective hydrogenation of unsymmetrically substituted cyclic anhydrides catalyzed by ruthenium complexes with mono-, di-, or triphosphine ligands produced the corresponding two isomeric lactones, where the regioselectivity was influenced by the bulkiness of substituent(s) on the anhydrides and of the phosphine ligands of catalyst.