Aluminum tri

Reduction of Cholest-5-en-3-one with Lithium Aluminum Tri-t-butoxy Deuteride. 

The reverse reaction, the so-called Oppenauer oxidation, is carried out by treating a substrate alcohol with aluminum tri-r-butoxide in the presence of acetone. By using an excess of acetone, the equilibrium can be shifted to the right, yielding the ketone 1 and isopropanol ... 

In further modifications of these norprogestins, reaction of norethindrone with acetic anhydride in the presence of p-toluene-sulfonic acid, followed by hydrolysis of the first-formed enol acetate, affords norethindrone acetate (41). This in turn affords, on reaction with excess cyclopentanol in the presence of phosphorus pentoxide, the 3-cyclopentyl enol ether (42) the progestational component of Riglovic . Reduction of norethindrone affords the 3,17-diol. The 33-hydroxy compound is the desired product since reactions at 3 do not show nearly the stereoselectivity of those at 17 by virtue of the relative lack of stereo-directing proximate substituents, the formation of the desired isomer is engendered by use of a bulky reducing agent, lithium aluminum-tri-t-butoxide. Acetylation of the 33,173-diol iffords ethynodiol diacetate, one of the most potent oral proves tins (44). ... 

Commercial end functional polymers have been converted to alkoxyamincs and used to prepare PKO-Worri-PS.040 The hydroxyl group of alkoxyamine 284 was used to initiate ring-opening polymerization of caprolactonc catalyzed by aluminum tris(isopropoxide) and the product subsequently was used to initiate S polymerization by NMP thus forming polycaprolactone-Wodr- P8.641 The alternate strategy of forming PS by NMP and using the hydroxyl chain end of the product to initiate polymerization of caprolactonc was also used. 

The cycloberbine 339 derived from coptisine (65) was reduced with lithium aluminum tri-tert-butoxyhydride to afford the trans-alcohol 340 along with a small amount of the cis-alcohol (Scheme 62). Treatment of 340 with ethyl chloroformate effected C-8—N bond cleavage and simultaneous oxyfunc-tionalization at C-8 with the desired stereochemistry to produce the oxazolidinone 341. This was hydrolyzed with potassium hydroxide and then underwent N-methylation to give ( )-ochrobirine (343). Similarly, the ochrobirine analog 344 was also obtained from berberine (15) (171). 

The 8-methyl-8,14-cycloberbine 364, derived from the protoberberine 324 via the betaine 363, was reduced with sodium borohydride or lithium aluminum tri-tert-butoxyhydride to give a diastereoisomeric mixture of cis-and trans-alcohols (7.8 1 or 1 7.8, respectively) (Scheme 64).t)n exposure to formaldehyde the mixture underwent N-hydroxymethylation and subsequent intramolecular substitution on the aziridine ring to give the oxazolidine 365. Removal of the hydroxyl group in 365 was accomplished by chlorination followed by hydrogenolysis with tributyltin hydride. Reductive opening of the oxazolidine 366 with sodium cyanoborohydride afforded ( )-raddeanamine (360), which has already been converted to ochotensimine (282) by dehydration. 

Several modifications have been made to organoaluminum-based catalysts. Methylaluminum bis(2,6-di-tert-butyl-4-alkylphenoxide) (MAD) shows high diastereofacial selectivity in carbonyl alkylation (Scheme 72).31 11 Aluminum tris(2,6-diphenylphenoxide) (ATPH) has been developed as a catalyst for conjugate addition reactions. Since a carbonyl group is stabilized by steric effect of ATPH, the 1,4-adduct is obtained selectively.312... 

Lithium aluminum tri-/-butoxyhydride in reduction of 3/3-acetoxy-5-pregnene-20-one, 45, 58... 

The phenomenon of organic EL was first demonstrated using a small-molecule fluorescent emitter in a vapor-deposited OLED device. The Kodak group first used metal oxinoid materials such as the octahedral complex aluminum tris-8-hydroxyquinoline (Alq3) (discussed above as an ETM) as the fluorescent green emitter in their pioneering work on OLED architectures [167],... 

K.A. Higginson, X. Zhang, and F. Papadimitrakopoulos, Thermal and morphological effects on the hydrolytic stability of Aluminum Tris(8-hydroxyquinoline) (Alq3), Chem. Mater., 10 1017— 1020 (1998). 

D.Z. Garbuzov, Y. Bulovic, P.E. Burrows, and S.R. Forrest, Photoluminescence efficiency and absorption of aluminum-tris-quinolate (Alq3) thin films, Chem. Phys. Lett., 249 433M-37 (1996). 

Aluminum tris(tetrahydroborate), 4 196 Aluminum wire, 17 833 Aluminum wrought alloy 1100, 2 328t chemical industry applications, 2 341 weathering, 2 336t... 

Lithium aluminum tri-tert-bu-toxyhydride, 53, 53 Lithium amide, bis(trimethyl-silyl), 53, 66 Lithium amide, diisopropyl-,... 

The hindered aluminum tris(2,6-diphenylphenoxide) is an effective promoter of Michael additions of enolates to enones.89... 

Robinson annulation can also be carried out using aluminum tris(2,6-diphenylphen-oxide) to effect the conjugate addition and cyclization. 

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