Lithium ferf-butoxide

A pentane solution of terf-butyllithium (purchased from either Alfa Inorganics, Inc. or Lithium Corporation of America, Inc.) was standardized by one of the previously described titration procedures (Note 1). If possible, it is desirable to use a freshly opened bottle of lert-butyllithium since previously used bottles of this reagent often contain lithium ferf-butoxide which will lead to formation of a contaminant in the final product (Note 10). 

The oxidations involving lithium ferf-butoxide reach completion (3 minutes for fluorenol, 12 minutes for xanthenol) much sooner than the corresponding reactions utilizing potassium terf-butoxide as base (35 minutes for fluorenol, 27 minutes for xanthenol). This behavior obviously involves Reaction 20 since the initial rates of oxidation were all approximately the same for the lithium- and potassium ferf-butoxide-catalyzed reactions. 

Solvents and potassium ferf-butoxide were purified or prepared as described (18). Rubidium-, sodium-, and lithium ferf-butoxides were prepared by the method described for potassium ferf-butoxide (20). Diphenylmethane (Eastman Kodak Co.) was vacuum-distilled. Fluorene... 

Fig. 8. The rection of see.-butyllithium with isoprene in hexane at 30°C. (a) normal conditions [sec.-BuLi] = 1.1 x 10 M, [isoprene] = 5 x 10 M (b) in the presence of 2 X 10 M lithium ferf.-butoxide (c) in the presence of sufficient polyisoprenyllithium to simulate 30% conversion at time zero [51 ].

Alkali metal salts with nucleophilic anions are notably good initiators for chloral anionic polymerization (Fig. 26). The most studied initiator is lithium ferf-butoxide. When 0.2 mole % of lithium ferf-butoxide (based on chloral) was added to neat chloral monomer at 60°C the alkoxide (CH3)3C0CH(CCl3)0 Li was formed instantaneously, but no further addition of chloral occurred. This reaction was observed by an NMR study of the system and confirmed by the chemical reactions of the product alkoxide, which acted as the initiator. Tertiary amines such as pyridine and NR3 where R is an alkyl group have been found to be good initiators for chloral polymerization. They are slower initiators than lithium... 

Peric s and coworkers have elucidated a facile and inexpensive route to determining the enantiomeric excess of primary amines. A regioselective and enantioselective epoxide ring opening of 108 with BF, followed by lithium ferf-butoxide catalyzed epoxide closure yielded 109, which was utilized as a resolution reagent. Through the use of 20 mol% of 109 relative to an amine, an ee determination could be performed on 110 via NMR without further purification <05OL3829>. 

Ni(II)/C (50.5 mg, 0.038 mmol, 0.74mmol/g), dppf (10.7 mg, 0.019 mmol), and lithium ferf-butoxide (74.3 mg, 0.90 mmol) were added to a flame-dried 5-mL round-bottomed flask under a blanket of argon at room temperature. Dry toluene (0.5 mL) was added by syringe and the slurry allowed to stir for 90 minutes. 

Aromatic Annulation. 7-Methoxy-3-(phenylsulfonyl)-l(3Y/)-isobenzofuranone (1) can be deprotonated at —78 °C with either lithium diisopropylamide or lithium ferf-butoxide to form a soluble yellow anion which can be utilized as an effective nucleophile in the Michael reaction. The initial anionic adduct cyclizes with concomitant elimination of benzenesulfinic acid to yield a 1,4-dihydroxynaphthalene which is unambiguously disubstituted at the 2- and 3-positions (eq l). ... 

Interestingly, Talalaeva et have prepared Zn(OBu )2 by the reaction of zinc chloride with lithium ferf-butoxide in ether solution. 

Peroxide-free THF and diethyl ether are distilled under argon from sodium benzophenone ketyl. Phenylmagnesium bromide (3 M solution, Aldrich) is obtained commercially. Anhydrous iron(II) halides (99.9-1-%) can also be obtained from Aldrich or prepared in the laboratory. Lithium ferf-butoxide (Aldrich) is used as received. 

In an inert atmosphere glove box, a 50 mL Schlenk flask is charged with [MgBr-(THF)2]4[FeH6l (0.200 g, 0.195 mmol) and a magnetic stirring bar. To this flask is added diethyl ether (12 mL) and lithium ferf-butoxide (0.062 g, 0.78 mmol). A reaction occurs within 1 h of stirring after 2 h, the yellow-brown mixture is... 

Di-0-isopropylidene-a-D-rtbo-hexofuranos-3-ulose (100) was treated with (chlorofluoromethylene)triphenylphosphorane (prepared by reaction of triphenylphosphine on difluorocarbene generated in situ by reaction of potassium ferf-butoxide with dichloro-fluoromethane), to give cis- and rans-3-C-(chlorofluoromethylene)-3-deoxy-l,2 5,6-di-0-isopropylidene-a-D-ribo- (101 and 103) and -xyfo-hexofuranoses (105 and 107), which, on treatment with lithium aluminum hydride, gave cis- and frans-3-deoxy-3-C-(fluoromethyl)-1,2 5,6-di-O-isopropylidene-a-D-rtbo- (102 and 104) and -xyZo-hexofura-... 

Pinocarveol has been prepared by the autoxidation of a-pinene,5 by the oxidation of /S-pinene with lead tetraacetate,6 and by isomerization of a-pinene oxide with diisobutylalumi-num,7 lithium aluminum hydride,8 activated alumina,9 potassium ferf-butoxide in dimethylsulfoxide,10 and lithium diethylamide.11 The present method is preferred for the preparation of pinocarveol, since the others give mixtures of products. It also illustrates a general method for converting 1-methylcy-cloalkene oxides into the corresponding exocyclic methylene alcohols.11 The reaction is easy to perform, and the yields are generally high. 

The nucleophilic addition of the a-lithiated alkyldiphenylphosphine oxide B to the carbonyl group of an aldehyde at the beginning of a Wittig-Horner reaction results in the phos-phorylated lithium alkoxide D. If the alkene synthesis is carried out in a single step, the Li of the intermediate D is, without workup, reversibly replaced by K by adding potassium-ferf-butoxide. In this way, the phosphorylated potassium alkoxide F is made available. Only in F... 

Single alkene diastereomers are accessible through a Wittig-Homer reaction only if it is performed in two steps (Figure 11.10). A 1 1 mixture of the phosphorylated lithium alkoxides syn- and anti-D is still formed but if the mixture is protonated at this point, the resulting phosphorylated alcohol diastereomers C can usually be separated without difficulty. The suitable diastereomer will be deprotonated with potassium-ferf-butoxide in the second step and then be converted into the stereouniform trans- or cis-alkene E via stereospecific oxaphosphetane formation and fragmentation. 

The application of strong bases to hydrocarbons which contain a sp3 hybridized carbon and a conjugated system may abstract a proton and form a fully conjugated carbanion. This reaction has several synonyms such as deprotonation, proton abstraction or metalation reactions. The most common bases are alkyl lithium derivatives, e.g., butyl lithium21 24). Sometimes the addition of tetramethylethylenediamine (TMEDA) or potassium ferf-butoxide is required especially when dianions and polyanions are prepared 24e,f). Ether solvents or hydrocarbon solvents are most common. This process can be demonstrated by the preparation of anthraene dianion 22 from 9,10-dihydroanthracene (1)25). The metalation reaction can also be carried out in the NMR tube. 

By contrast with the reaction of lithium rert-butoxide with triphenylbismuth diacetate, which gave ferf-butyl phenyl ether (r-BuOPh) in 66% yield, the same reaction with triphenylantimony diacetate appeared to stop at the stage of the formation of (/err-butoxy)acetoxytriphenylantimony. The ligand coupling did not proceed, and re/t-butanol was recovered after hydrolysis of the mixture. ... 

The first total synthesis of (+)-hydantocidin (1) in an optically active form has established its absolute configuration (Scheme 9). The synthesis was started by aldol condensation of 4-0-benzyl-2,3-C -isopropylidene-D-threose (78) and l-A -acetyl-3-Af-(4-methoxybenzyl)-hydantoin (76) ° in the presence of potassium ferf-butoxide to afford a mixture of Z- and -isomers 79 (71%) and 80 (14%), respectively. Treatment of the mixture of 79 and 80 with p-toluenesulfonic acid afforded the cyclized product 82 and 81. Alternatively, treatment of (2A,3i )-4-benzyloxy-2,3-epoxybutanal (84) with lithium derivative of 77 afforded 85, which upon treatment with lithium bis(trimethylsilyl)amide... 

OPTAL (71-23-8) Forms explosive mixture with air (flash point 59°F/15°C). Violent reaction with strong oxidizers, potassium-ferf-butoxide, triethylaluminum. Reacts, possibly violently, with acetaldehyde, alkalineearth and alkali metals, strong acids, strong caustics, aliphatic amines, benzoyl peroxide, chromic acid, chromium trioxide, dialkylzincs, dichlorine oxide, ethylene oxide, hypochlorous acid, isocyanates, isopropyl chlorocarbonate, lithium tetrahydroaluminate, nitric acid, nitrogen dioxide, nitronium tetrafluoroborate(l-), pentafluoroguanidine, phosphorus pentasulfide, tangerine oil, triisobutylaluminum. Attacks some plastics, rubber, and coatings. 

In contrast to the insoluble, nonvolatile nature of the simple alkoxo-derivatives of alkali metals, their perfluoro-alkoxo derivatives are comparatively more soluble in polar solvents like acetonitrile, acetone and ether. Thus the perfluoro ferf-butoxides of lithium and sodium (MOC4F9) have been found to be high-melting solids which can be distilled under reduced pressures." " The corresponding potassium perfluoro ferf-butoxide could also be sublimed at 140°/0.2mm pressure." " The high volatilities of lithium, sodium, and potassium ferf-butoxides might well arise from low molecular complexities of... 

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