Benzene-, diisobutylaluminum

To a magnetically stirred solution of diisobutylaluminum hydride (5.4 ml of 1.5 M solution in toluene) was added a solution of trans,trans-diester (600 mg, 2.0 mmol) in 15 ml of anhydrous benzene at a rate sufficient to maintain the... 

Diisobutylalane (diisobutylaluminum hydride) (0.85 mol) is added under nitrogen over a period of 10 hours to a stirred solution of 34.4 g (0.2 mol) of diethyl fumarate in 160 ml of benzene. The temperature rises to 50°. After standing overnight at room temperature, the reaction mixture is decomposed by the addition of 76.8 g (2.4 mol) of methanol in 150 ml of benzene followed by... 

Oxo-cyclopentene and 3-oxo-cyclohexene react with diisobutylaluminum benzene-tellurolate to produce diisobutylaluminum 3-phenyltelluro-l-cycloalken-l-olates that condensed with butanal and benzaldehyde. The resulting 3-oxo-2-[(organo)hydroxymeth-yl]-l-phenyltcllurocycloalkanes were converted by 3-chloroperoxybenzoic acid to 3-oxo-2-[(organo)hydroxymethyl]-cycloalkenes2. 

The reverse regiocontrol, giving 1,2-diols, is observed with DIBAL-H (diisobutylaluminum hydride). The remarkable effect of titanium tetraisopropoxide as an additive to lithium borohydride has also been reported. In this reaction benzene is a better solvent than THF, probably because a Ti complex using both oxygens in epoxy alcohols is formed in benzene before the hydride attack. Other metal hydrides used include sodium hydrogen telluride (NaHTe) and an ate complex derived from DIBAL-H and butyllithium, both of which reduce epoxides to alcohols, although they have been tested with only a small number of examples. In the former case the reaction may proceed via a 2-hydroxyalkyltellurol intermediate. 

In a paper published along with that of Stevens and Wentland20 and in agreement with these authors, Keely and Tahk23 reported the independent synthesis of dl-mesembrine, also from I-methyl-3-(3,4-dimethoxyphenyl)-2-pyrroline and methyl vinyl ketone. In their work the cyclopropyl derivative 3b was prepared from the reaction of the anion of 3,4-dimethoxyphenylacetonitrile (lc) with ethylene dibromide in dimethyl sulfoxide and its sodium salt as solvent and base. Reduction with ethereal diisobutylaluminum hydride gave the aldehyde, which was condensed with excess methylamine in benzene-ether solution with calcium oxide as the dehydrating agent. 

The complex is obtained from tri-n-butylphosphine and copper(I) hydride, prepared by reduction of copper(I) bromide with diisobutylaluminum hydride at —50°. The complex is a useful reducing agent it reduces iodobenzene to benzene (80% yield) and benzoyl chloride to benzaldehyde (50% yield). In addition the complex reduces primary, secondary, and tertiary alkyl-, vinyl-, and arylcopper(l) compounds to the corresponding hydrocarbons in high yields, under mild conditions and with no rearrangements.1... 

Startg. enone-acid treated with 2 equivalents diisobutylaluminum hydride in benzene-methylene diloride, then quenched with 20%-sulfuric acid -> product. Y 89%. S.C. Welch and R.Y.Wong, Tetrah. Let. 1972, 1853. 

The synthesis of trans-3-acyl- 3-lactam methyl esters 107 has been reported by Almqvist and coworkers [81, 82] by the Staudinger reaction of ketenes, generated from the Meldrum s acids 105, with methyl (i )-thiazoline-4-carboxylate 106 in benzene in the presence of hydrogen chloride (Scheme 3.36). An exceptionally low yield of 38% was obtained in the reaction of acetylketene. These esters could then be selectively reduced to the corresponding aldehydes 108 in moderate yields using diisobutylaluminum hydride (DIBAL-H). The Meldrum acids are well-known precursors of ketenes [83, 84]. They undergo a pericyclic reaction under thermal influence to generate ketenes with the release of carbon monoxide and acetone. 

Diisobutylaluminum hydride added to a soln. of triethyl orthobenzoate in dry benzene at such a rate that the temp, does not exceed 30°, and stirred 1 hr. at this temp, benzaldehyde diethyl acetal. Y ... 

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