Chloride and Lithium Hydride

VCI3 + LiH(l 1) reduces aldehydes, ketones, and esters to the corresponding alcohols in high yields. Terminal olefins are also reduced but not alkynes or internal olefins [21]. 

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C.M. Austin et al, JChemEduc 36, (Feb 1959) (15 refs) Aluminum-Lithium Hydride or Lithiui umlnohydride, AlLiH4, wh solid prep aluminum chloride and lithium hydrid... 

Aluminum-Lithium Hydride or Lithium Al uminohydride, AlLiH4, wh solid prepd fre aluminum chloride and lithium hydride in... 

G-S.Perrott N. A.Tolch, Bull 349, (1932)(Liquid oxygen exp 3)A.D.Kirshenhaum, Research Institi Temple University, Phil a, Pa, Final ] on Fundamental Studies of New Exp Reactions for Office of Ordnance Re Contract No DA-36-034-0RD-1489(3C 1936) 4)Anoiv C EN 35,90(17 Jun 5)Anon, C EN 35, 12 14(15 Aug 1 6 C.M. Austin et al, JChemEduc 36, (Feb 1959) (15 refs) Aluminum-Lithium Hydride or Lithiui uminohydride, AlLiH, wh solid prep aluminum chloride and lithium hydrid... 

Eu304(cr) can be prepared by reacting stoichiometric amounts of EuO and EuyOs in a sealed tube at 1170 K, which indicates that it is stable with respect to the end-member oxides, or by other methods, e.g. reaction of the sesquioxide, the oxide chloride and lithium hydride [83], or even by high-temperature decomposition of EuO [47] ... 

The condensation is usually carried out by adding a solution containing equimolar amounts of the allyl halide and the aldehyde or ketone to a solution of at least two equivalents of chromium-(II) chloride in THF at 0 5°C. Frequently, the less precious component is used in 50-100% excess. Although commercially available anhydrous chromium(II) chloride can be utilized (Method B), its in situ preparation from chromium(III) chloride and lithium aluminum hydride (Method A) is often preferred. The removal of chromium and aluminum hydroxide, which are formed on aqueous workup, can be accomplished by filtration in the presence of a filtration aid. 

Cyclobutanecarboxaldehyde has been prepared in very low yield by the Rosenmund reduction procedure.6 A 46% yield of the 2,4-dinitrophenylhydrazone derivative has also been reported, with the aldehyde formed as an intermediate, in the reaction of the acid chloride and lithium tri-Mmtoxyaluminum hydride at —78° in diglyme.7... 

W7. Nernst has suggested that the hydrogen in lithium hydride plays the part of a halogen, and likens the reaction LiOH + H2=H20 +LiH with LiOH+HCl =H20+LiCl he shows similarities between lithium hydride and chloride in their crystalline form, at. vol., at. lit., heat of formation, coloration of ultra-violet rays, etc. The electrolysis of molten lithium hydride is also analogous with that of fused lithium chloride. Since lithium hydride is completely hydrolyzed in aq. soln., it is assumed that hydrogen acts as a very weak acid. 

Recently, zinc in tetrahydrofuran with a catalytic amount of iodine or reduced titanium [preformed from titanium(IV) chloride and lithium aluminum hydride in tetrahydrofuran] has also been used to prepare difluorocyclopropanes. 

A fairly efficient synthesis of 1-chloro-l-fluorocyclopropanes under mild conditions is based on the reduction of trichlorofluoromethane by a zerovalent titanium species in the presence of an alkene (Table 6). The metal is formed in the reaction system from titaniura(IV) chloride and lithium aluminum hydride. ... 

Reductive 1,2-eIimination of chlorine and bromine from adducts of l-bromo-2-chlorocyclo-propene (see Section 5.2.2.1.2.5.) with oxygen and sulfur hetarenes has served in the synthesis of a number of cycloproparenes. This transformation is effected by low-valent titanium together with lithium aluminum hydride or an organolithium compound. Thus, reaction of the adduct 3 of l-bromo-2-chlorocyclopropene and 1,3-diphenylisobenzofuran with tita-nium(III) chloride and lithium aluminum hydride overnight in tetrahydrofuran led to elimination of both halogens together with extrusion of the oxygen and formation of 2,7-diphenyl-l/f-cyclopropa[ ]naphthalene (4) in 72% yield. 

The reaction with simple, nonbenzenoid furans was less successful. Thus, reaction of tita-nium(III) chloride and lithium aluminum hydride with the adduct 8 (R = Me) of l-bromo-2-chlorocyclopropene and 2,5-dimethylfuran gave only 30% of the cycloheptatriene 10 (R = Me) and no cycloproparene. With the 2-methylfuran adduct 8 (R = H), an additional 30% of 2-methyl-l/f-cyclopropabenzene (9, R = H) was obtained. 

Analogous reaction with the adduct 11 of thiophene 1,1-dioxide gave only a very poor yield of the substituted cycloheptatriene 12. The latter could be converted to l//-cyclopropabenzene (13) in 11% yield by reaction with titanium(III) chloride and lithium aluminum hydride in tetrahydrofuran, or in 50% yield by reaction with butyllithium in hexane. 

The less highly substituted bond of a siloxycyclopropane is quantitatively opened by mercury(II) acetate to afford -mercurio ketones. In the same pot these are transformed to a-methylene ketones in virtually quantitative yield on treatment with one equivalent of palladium(II) chloride in the presence of lithium chloride and lithium carbonate (2 equiv each). Catalytic amounts of palladium(II) chloride (0.1 equiv) are sufficient in the second step, if two equivalents of copper(II) chloride is added as an oxidant. Mechanistically, the second step involves trans-metalation to a j -palladio ketone followed by /i-hydride elimination. In bicyclic systems it is sometimes necessary to add triethylamine to avoid HPdCl induced double-bond shifts in the reaction product. Examples are the rearrangements of 18, 20 and 22. ... 

Silicon, unlike carbon, does notiorm a very large number of hydrides. A series of covalently bonded volatile hydrides called silanes analogous to the alkane hydrocarbons is known, with the general formula Si H2 + 2- I uf less than ten members of the series have so far been prepared. Mono- and disilanes are more readily prepared by the reaction of the corresponding silicon chloride with lithium aluminium hydride in ether ... 

Trimethylene dibromide (Section 111,35) is easily prepared from commercial trimethj lene glycol, whilst hexamethylene dibromide (1 O dibromohexane) is obtained by the red P - Br reaction upon the glycol 1 6-hexanediol is prepared by the reduction of diethyl adipate (sodium and alcohol lithium aluminium hydride or copper-chromium oxide and hydrogen under pressure). Penta-methylene dibromide (1 5-dibromopentane) is readily produced by the red P-Brj method from the commercially available 1 5 pentanediol or tetra-hydropyran (Section 111,37). Pentamethylene dibromide is also formed by the action of phosphorus pentabromide upon benzoyl piperidine (I) (from benzoyl chloride and piperidine) ... 

Lithium aluminium hydride LiAlH is a useful and conveuient reagent for the selective reduction of the carbonyl group and of various other polar functional groups. It is obtained by treatment of finely powdered lithium hydride with an ethereal solution of anhydrous aluminium chloride ... 

Aromatic polysulfites can be produced if bisphenols, eg, bisphenol A, are heated with diphenyl sulfite in the presence of lithium hydride (112). Halosulfates and Halosulfites. A general method for the preparation of alkyl halosulfates and halosulfites is the treatment of the alcohol with sulfuryl or thionyl chloride at low temperatures while passing an inert gas through the mixture to remove hydrogen chloride (113). 

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