Lithium isopropyl alcohol

Products from aminoalcohols and TYZOR TPT were obtained by a2eotropiag the isopropyl alcohol with ben2ene (121,122). From trimethylethylenediamine, dimethylethanolamine, and dimethylisopropanolamine with TYZOR TPT, the orange (11), the yellow (12), and the pale-green (13) were obtained, respectively. The lithium salt of the ligand, derived from C H Li, combiaed with (RO)2TiCl ia hexane has also been used (123). 

While keeping the collected deuterioammonia at dry ice-isopropyl alcohol temperature, lithium wire (10 mg) is added, followed by a solution of 3/3-hydroxy-5a-cholest-7-en-6-one (161 50 mg) in anhydrous tetrahydrofuran (4 ml). The reaction mixture is stirred for 20 min, the cooling bath is then removed and the ammonia is allowed to boil under reflux for 40 min. A saturated solution of ammonium chloride in tetrahydrofuran is added dropwise until the deep blue color disappears and then the ammonia is allowed to evaporate. The residue is extracted with ether and the organic layer washed with dilute hydrochloric acid and sodium bicarbonate solution and then with water. Drying and evaporation of the solvent gives a semicrystalline residue which is dissolved in acetone and oxidized with 8 N chromic acid solution. After the usual workup the residue is dissolved in methanol containing sodium hydroxide (0.2 g) and heated under reflux for 1 hr to remove any deuterium introduced at C-5 or C-7. (For workup, see section II-B). 

A mixture containing 186 g (0.20 mol) of 2-aminopyridine, 0.55 g of lithium amide and 75 cc of anhydrous toluene was refluxed for 1.5 hours. Styrene oxide (12.0 g = 0.10 mol) was then added to the reaction mixture with stirring over a period of ten minutes. The reaction mixture was stirred and refluxed for an additional 3.5 hours. A crystalline precipitate was formed during the reaction which was removed by filtration, MP 170°C to 171°C, 1.5 g. The filtrate was concentrated to dryness and a dark residue remained which was crystallized from anhydrous ether yield 6.0 g. Upon recrystallization of the crude solid from 30 cc of isopropyl alcohol, 2.0 g of a light yellow solid was isolated MP 170°C to 171°C. 

Reacts with vapors of sodium with luminescence at about 260°C. Reacts explosively with thionyl chloride or potassium reacts violently with hexafluoro isopropylidene, amino lithium, ammonia, and strong acids reacts with tert-butyl azidoformate to form explosive carbide reacts with 24-hexadiyn-l, 6-diol to form 2, 4-hexadiyn-l, 6-bischloro-formate, a shock-sensitive compound reacts with isopropyl alcohol to form isopropyl chloroformate and hydrogen chloride thermal decomposition may occur in the presents of iron salts and result in explosion. 

In practice, the equivalent synthon of 2 was l-cyano-4,5-dimethoxybenzocyclobutene 22 (Scheme 3.7) which on heating generates a reactive o-quinodimethane by a conrotatory electrocyclic ring opening process (Cf. Scheme 3.7) and reacts, at 150-160 °C, with the 3,4-dihydroisoquinoleine 23 to give 80-88%yield of 13-cyanoprotoberberine 24. A simple reductive decyanation with lithium in liquid ammonia in the presence of isopropyl alcohol afforded xylopinine (19) in 84.6% yield [19]. 

Several reagents reduce aldehydes preferentially to ketones in mixtures of both. Very high selectivity was found in reductions using dehydrated aluminum oxide soaked with isopropyl alcohol and especially diisopropylcarbinol [755], or silica gel and tributylstamane [756]. The best selectivity was achieved with lithium trialkoxyalumimm hydrides at —78°. In the system hexanal/ cyclohexanone the ratio of primary to secondary alcohol was 87 13 at 0° and 91.5 8.5 at —78° with lithium tris(/er/-butoxy)aluminum hydride [752], and 93.6 6.4 at 0° and 99.6 0.4 at —78° with lithium tris(3-ethyl-3-pentyl-oxy)aluminum hydride [752],... 

Chemical reduction of aromatic aldehydes to alcohols was accomplished with lithium aluminum hydride [5i], alane [770], lithium borohydride [750], sodium borohydride [757], sodium trimethoxyborohydride [99], tetrabutylam-monium borohydride [777], tetrabutylammonium cyanoborohydride [757], B-3-pinanyl-9-borabicyclo[3.3.1]nonane [709], tributylstannane [756], diphenylstan-nane [114], sodium dithionite [262], isopropyl alcohol [755], formaldehyde (crossed Cannizzaro reaction) [i7i] and others. 

Reduction of unsaturated ketones to unsaturated alcohols is best carried out Nit v complex hydrides. a,/3-Unsaturated ketones may suifer reduction even at the conjugated double bond [764, 879]. Usually only the carbonyl group is reduced, especially if the inverse technique is applied. Such reductions are accomplished in high yields with lithium aluminum hydride [879, 880, 881, 882], with lithium trimethoxyaluminum hydride [764], with alane [879], with diisobutylalane [883], with lithium butylborohydride [884], with sodium boro-hydride [75/], with sodium cyanoborohydride [780, 885] with 9-borabicyclo [3.3.1]nonane (9-BBN) [764] and with isopropyl alcohol and aluminum isopro-... 

Since sodium borohydride usually does not reduce the nitrile function it may be used for selective reductions of conjugated double bonds in oc,/l-un-saturated nitriles in fair to good yields [7069,1070]. In addition some special reagents were found effective for reducing carbon-carbon double bonds preferentially copper hydride prepared from cuprous bromide and sodium bis(2-methoxyethoxy)aluminum hydride [7766], magnesium in methanol [7767], zinc and zinc chloride in ethanol or isopropyl alcohol [7765], and triethylam-monium formate in dimethyl formamide [317]. Lithium aluminum hydride reduced 1-cyanocyclohexene at —15° to cyclohexanecarboxaldehyde and under normal conditions to aminomethylcyclohexane, both in 60% yields [777]. 

Arnett and Moe studied the protodelithiation of organolithiums with isopropyl alcohol in hexane/ether mixtures. These authors found protodelithiation enthalpies for n- and iec-butyl lithium of —209.2 4.2 and —220.9 2.9, respectively. The difference between their enthalpies of reaction, and so of the enthalpies of formation of the two organolithiums, is 11.7 5.1 kJmor, about half the difference between these species as found in Table 1. The protodelithiation enthalpy of terf-butyl lithium is —237.7 7.5 kJmoP. From equation 10 with n-butyl lithium as the benchmark species, and the butane hydrocarbons in their liquid reference states, the derived enthalpy of formation of ferf-butyl lithium is —87.5 kJmoP, in good agreement with that found before by Hohn . 

E. F. Anthon found ammonium sulphate to be insoluble in absolute alcohol, while alcohol of sp. gr. 0 872 dissolves O 2 grm. of the salt, and in more dil. alcohol the salt is more soluble. J. J. Pohl obtained an analogous result. J. Traube and 0. Neuberg found that with mixtures of alcohol and water, the soln. separates into two layers with certain couc.—e.g. with alcohol with a sp. gr. over 0 9530 at 15°— in the lower aq. layer, the mol. ratio of the three components is approximately constant, indicating that a definite compound is probably formed. These soln. have been studied by G. Bodlander, F. A. H. Schreinemakers, and C. A. L. de Bruyn. This phenomenon, layer separation, has also been observed with lithium sulphate in alcohol-water soln. C. E. Linebarger found the solubility in aq. isopropyl alcohol at 20° to be 0 4, 2 0, and 6 7 grms. (N 114)2804 per 100 grms. of soln. in the presence of 70, 50, and 20 per cent, of CsH7OH. W. Erdmann found ammonium sulphate to be insoluble in acetone. 

To a solution of the N-methoxy-N-methyl-2,8-bis(trifluoromethyl)-quinoline-4-carboxamide amide (10 g, 28.4 mmol) in anhydrous ether (100 ml) was added a solution of 2-pyridyl lithium (Pinder et al (J. Med. Chem. 1968, 11, 267)) [formed by addition of 2-bromopyridine (3.3 ml, 34.6 mmol) to a solution of butyl lithium (29.7 ml of a commercial 1.6 M solution, diluted with an equal quantity of ether) at -78°C] at -78°C. Analysis of the reaction by TLC after 10 min showed that no starting material remained. The reaction was allowed to warm to room temperature, then poured into aqueous ammonium acetate, and extracted with ether, the combined organic layers washed with brine and dried (MgS04). Filtration through a pad of silica gel using ethyl acetate-hexane (1 1) afforded 9.0 g (84%) of the crude 2,8-bis(trifluoromethyl)-4-quinolinyl-2-pyridinylmethanone. This was recrystallised from isopropyl alcohol to give the product as colourless needles, identical to that described in the literature (Hickmann et al. Pinder et al. Ohnmacht et al. and Adam et al. (Tetrahedron 1991, 36, 7609)). 

Two large-scale syntheses were reported by Quaedflieg et al. at Tibotec.31 Chiral synthon 20, obtained from ascorbic acid, was converted to a,p-unsaturated ester 21 in 92% yield and E/Z ratio was > 95 5. Michael addition of nitromethane to 21 was carried out with DBU as base to provide 22 in 80% yield and a syn/anti ratio of 5.7 1. A Nef reaction then converted 22 to a mixture of lactone 23 (major, 56%) (a/p = 3.8 1) and ester 24 (minor). The a-23 was obtained via recrystallization in isopropanol (37%), with high enantiomeric purity (> 99%). Isomerization of P-23 followed by recrystallization in isopropyl alcohol gave an additional 9% yield of a-23. It is interesting that most of 24 remained in the aqueous layer. Lithium borohydride reduction of a-23 followed by acid-catalyzed cyclization resulted in (-)-ll. 

A mixture consisting of methyl 4-methoxybenzoate (7.47 mmol) and 4-methoxyphenylacetonitrile (6.79 mmol) dissolved in 15 ml THF was added to 20 ml 2.0 M lithium diisopropylamide at — 10°C, then gradually warmed to ambient temperature, and stirred overnight. It was then quenched with water and concentrated. The residue was recrystallized using isopropyl alcohol and the product isolated in 65% yield as a red-orange solid, mp = 213°C. 

The trapped electrons were formed simply by depositing alkali metal atoms on ice or solid alcohols at 77°K. Studies were made of the reactions between sodium or potassium atoms and ice (HgO or D2O), methanol, ethanol, isopropyl alcohol, t-butyl alcohol or dodecanol. The reactions of caesium, rubidium and lithium with ice were also investigated. The deposits were highly coloured and the optical and e.s.r. spectra showed that the electron was no longer associated with the alkali metal ion but had been transferred completely to the solid matrix. 

Under the appropriate conditions it undergoes hazardous reactions with Al, tert-butyl azido formate, 2,4-hexadiyn-l,6-diol, isopropyl alcohol, K, Na, sodium azide, hexafluoroisopropylideneamino lithium, lithium. When heated to decomposition or on contact with water or steam it will react to produce toxic and corrosive fumes of CO and Cr. Caution-. Arrangements should be made for monitoring its use. 

Intermolecular cycloaddition of 1-cyanobenzocyclobutene 15 to 3,4-dihydro-/ -carboline (14) was effected at 140-150°C without solvent to give regioselectively the 14-cyanohexadehydroyohimbane 16 (85%). This was de-cyanated by treatment with lithium and liquid ammonia/isopropyl alcohol to afford the hexadehydroyohimbane 17 (Scheme 3) (74T1053). 

It is unreasonable to believe that a model that assumes that the radicals diffuse freely in solution could account for such results. On the other hand, a surface-bound radical is fully in accord with them. Compound (S)-(-l-)-18 behaves similarly when exposed to metal surfaces of alkali metals in hydroxylic solvents [94]. As in the Grignard reagent formation, when a solution of (S)-(-f)-l-bromo-l-methyl-2,2-diphenylcyclopropane 18 in methanol, isopropyl alcohol, or r-butenol was exposed to an alkali metal, such as lithium, sodium, or potassium, the resulting hydrocarbon (K)-( —)-l-methyl-2,2-diphenylcyclopropane 13 was shown to be optically active and with retained configuration, as shown in Table 19 and Scheme 40. 

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