25409-08-9

Usage

Preparation

By isomerization of 2-butyl-3-butene-1,2-diol in acid media.

InChI:InChI=1/C8H14O/c1-3-5-6-8(4-2)7-9/h4,7H,3,5-6H2,1-2H3/b8-4-

Upstream product

• 71504-20-6 (E)/(Z)-2-Ethyl-1-trimethylsiloxy-1-hexene 
• 266683-59-4 2-bromo-1,1-dimethoxy-2-ethylhexane 
• 14250-95-4 2-ethylhexanal dimethyl acetal 

Relevant academic research and scientific papers

Novel Preparation of α,β-Unsaturated Aldehydes. Benzeneselenolate Promotes Elimination of HBr from α-Bromoacetals

Acetalization, α-bromination, nucleophilic phenylselenenylation, oxidative elimination/hydrolysis was investigated as a novel protocol for the α,β-dehydrogenation of aldehydes. Treatment of acetals with bromine in methylene chloride afforded the corresponding α-bromoacetals in 80-90% yields. Nucleophilic phenylselenenylation was then conveniently effected by treatment with benzenese-lenolate generated in situ in dimethyl sulfoxide from diphenyl diselenide, hydrazine and potassium carbonate. Unbranched α-bromoacetals cleanly afforded substitution products whereas β- and γ-branched ones gave substantial amounts of α,β-unsaturated acetals via formal loss of hydrogen bromide. Oxidative elimination/hydrolysis of these mixtures afforded α,β-unsaturated aldehydes in 50-80% overall yields. In the case of tertiary α-bromoacetals, treatment with benzeneselenolate afforded only dehydrobromination products as mixtures of isomers. The presence of at least a catalytic amount of the organoselenium reagent was found to be crucial for olefin formation. A SET-mechanism, involving benzeneselenolate-induced electron transfer to the halide, loss of bromide ion, and hydrogen atom or proton/electron was proposed for the benzenselenolate-promoted elimination reaction. Experiments designed to trap carbon-centered radicals in intramolecular cyclization or ring-opening reactions failed to provide any evidence for free-radical intermediates.

THE RECTION OF ALDEHYDE ENOL SILYL ETHERS WITH LEAD(IV)ACETATE

The treatment of aldehyde enol silyl ethers 1 with lead(IV)acetate (LTA) using methylene chloride as solvent gives rise to the production of α-acetoxy aldehydes 2 and glycolic ester derivatives 3 or enals 5.Structrural variations in 1 are used to explained the divergent trends.When 1 is treated with LTA/KOAc/AcOH, high yields of the corresponding α-acetoxy aldehydes 2 are obtained with the formation of 3 and 5 being subverted.