Magnesium methyl- iodide

Note that ethylene oxide reacts with the Grignard reagent to gi e a 2-substi tuted ethanol e.g. with methyl magnesium iodide ... 

Dimethyl ethyl carbinol (2-methy 1-2-butanol or amyl alcohol), CH3CHjCOH(CH3).2. From ethyl propionate and methyl magnesium iodide. Collect the tertiary alcohol at 100-102°. 

The rate of the reaction decreases with increasing number of substituents in the acetylenic halide, and it is higher with acetylenic bromides than with the corresponding chlorides. Methyl magnesium iodide gives equal amounts of 1,1- and 1,3--substitution products, whereas tert.-butylmagnesium bromide does not react. However, for some tert.-butyl substituted allenes there exists an attractive com-... 

The present procedure was developed from those of Wallach and Freylon, based upon the general method discovered by Leuckart. a-Phenylethylamine also can be prepared satisfactorily by the reduction of acetophenone oxime with sodium and absolute alcohol or sodium amalgam, but the reagents are more expensive and the processes less convenient. The amine has been obtained by reducing acetophenone oxime electro-lytically, by reducing acetophenone phenylhydrazone with sodium amalgam and acetic acid, from a-phenylethyl bromide and hexamethylenetetramine, and by the action of methyl-magnesium iodide upon hydrobenzamide, as well as by other methods of no preparative value. 

Rao prepared 2a-methyl-5a-cholestan-2i -ol (5) by reaction of methyl-magnesium iodide with 5a-cholestan-2-one (4). The 2i -configuration of the hydroxyl group was established by converting (5) to the 2a-methyl-2j5,19-epoxide (6) with lead tetraacetate and iodine in boiling benzene. 

Epoxide (88) is converted to C-norpregnane (89) in 60% yield by methyl-magnesium iodide in refluxing ether-benzene. No rearrangement to the C-norsteroid occurs with dimethylmagnesium. 

Formyl- and 4-bromo-3-formyl-isothiazole have been prepared in good yield from the dibromomethyl compounds obtained by side-chain halogenation of the appropriate 3-methylisothiazole with N-bromosuccinimide. 3-Acetyl- and 3-acetyl-4-bromo-isothiazole have been prepared from the 3-cyanoisothiazoles and methyl magnesium iodide. ... 

Conjugate addition of methyl magnesium iodide in the presence of cuprous chloride to the enone (91) leads to the la-methyl product mesterolone (92) Although this is the thermodynamically unfavored axially disposed product, no possibility for isomerization exists in this case, since the ketone is once removed from this center. In an interesting synthesis of an oxa steroid, the enone (91) is first oxidized with lead tetraacetate the carbon at the 2 position is lost, affording the acid aldehyde. Reduction of this intermediate, also shown in the lactol form, with sodium borohydride affords the steroid lactone oxandrolone... 

An ester of alanine with an arylaliphatic alcohol has shown promise as a non-tricyclic antidepressant. It may be speculated that the hindered milieu of the ester linkage protects the compound from hydrolysis by endogenous esterases. The preparation starts by reaction of pheny-lacctate 83 with methyl magnesium iodide to give tertiary carbinol 84. Acylation with 2-bromo-]>ropionyl bromide leads to ester 85 displacement of halogen with ammonia leads to alaproclate ( 6) [211. 

Wallach has prepared a-phellandrene synthetically from sabinenic acid by oxidising it to sabina ketone with potassium permanganate. This ketone was converted into its semicarbazone, and the latter compound treated with dilute sulphuric acid, when sabina ketone is not regenerated, but an isomer, which was found to be isopropyl-hexenone. By the interaction of this body with methyl-magnesium iodide, loss of water occurs with a simultaneous conversion into a-phellandrene, which appears to be a mixture of the dextro- and laevo- varieties. This syntheticallj prepared a-phellandrene has the following characters —... 

To an ethereal solution of methyl magnesium iodide prepared from 26.7 g (1.1 mols) of magnesium and 160 g (1.13 mols) Of methyl iodide in 200 cc of dry ether, is added a solution of 79 g (0.72 mol) of cyclopentylacetonitrile in 100 cc of dry ether. The reaction mixture is refluxed for 4 hours. The reaction mixture is then decomposed with ice in the usual way, and the ether layer containing the cyclopentylacetone is separated, is dried over anhydrous magnesium sulfate and the ether removed by evaporation. The residue comprising cyclopentylacetone is purified by distillation in vacuo. The cyclopentylacetone boils at 82° to 84°C at about 32 mm pressure. 

One of the first examples of this type of reaction, using a chiral alcohol as an auxiliary, was the asymmetric synthesis of 2-hydroxy-2-phenylpropanoic acid (atrolactic acid, 3, R1 =C6H5 R3 = CH3) by diastereoselective addition of methyl magnesium iodide to the men-thyl ester of phcnylglyoxylie acid4,5 (Table 22). 

A methyl group can be placed on cobalt in dicyano[cobyrinic acid heptamethyl ester] when it is treated with excess methyl magnesium iodide (the ester side chains being converted into tertiary alcohol groups). The alkylation could also be achieved using lithium alkyls (176). Presumably this reaction would be successful with any corrinoid which is soluble in solvents compatible with Grignard reagents. 

Fujisawa et al. [Ill] have reported that the magnesiiun complex prepared from chiral 2-[2-[(tolylsulfonyl)amino]phenyl]-4-phenyl-l,3-oxazoline 81 and methyl-magnesium iodide was efficient, in a stoechiometric amount, for promoting the enantioselective Diels-Alder reaction of 3-alkenoyl-l,3-oxazohdin-2-one with cyclopentadiene (Scheme 45) leading exclusively to the endo adducts in up to 92% ee. The use of 10 mol% of the complex led to an important decrease in enantioselectivity of the product (51% ee). 

The stereospecific conversion of menthyl arenesulphinates into chiral aryl methyl sulphoxides may also be achieved by means of methyllithium . The reaction of methyllithium with diastereoisomerically or enantiomerically pure arenesulph-inamides 283 was found to give optically active aryl methyl sulphoxides 284 (equation 156). The preparation of optically active sulphoxides 285 and 286, which are chiral by virtue of isotopic substitution (H - D and - respectively), involves the reaction of the appropriate non-labelled menthyl sulphinates with fully deuteriated methyl magnesium iodide (equation 157) and with benzylmagnesium chloride prepared from benzyl chloride labelled with carbon (equation 158). 

Metljylcoumarone has been prepared by the cyclization of ethyl a-phenoxyacetoacetate followed by hydrolysis and decarboxylation of the resulting ethyl 3-methylcoumarilate,3 4 by debromination and rearrangement of 3,4-dibromo-4-methyl-coumarin to 3-methylcoumarilic acid followed by decarboxylation,4-6 by cyclization of phenoxyacetone with concentrated sulfuric acid,6 and by treatment of 3-coumaranone with methyl-magnesium iodide followed by dehydration of the resulting car-binol.7... 

The reaction of isopropylidene piperidinomethylenemalonate and methyl magnesium iodide in a mixture of diethyl ether and THF at room temperature gave isopropylidene ethylidenemalonate in 92% yield (88JA1880) (Scheme 58). 

The copper-catalyzed conjugate addition of methyl magnesium iodide to cyclohexenone and trapping the enolate as its trimethylsilyl enol ether, followed by a trityl hexachloro-antinomate-catalyzed Mukaiyama reaction, is apphed to / -(—jcarvone. C-2, C-3 functionalized chiral cyclohexanones are converted into their a-cyano ketones, which are submitted to Robinson annulation with methyl vinyl ketone. Highly functionalized chiral decalones are obtained that can be used as starting compounds in the total synthesis of enantiomerically pure clerodanes (equation 70). 

Tri-tert-butyl-X -phosphorin24 readily reacts with bromine and with chlorine. Mach oxidizing with bromine in CCI4, could not isolate a crystalline product. The brown colour of the addition product of one mole Br2 to one mole 24 disappeared with water and the crystalline 2-hydro-phosphinic acid 85b could be isolated in 45% yield. Methyl-magnesium-iodide or red phosphorus yielded 2.4.6 tri-tert-butyl-X -phosphorin 24. It seems reasonable to suppose that on bromination l.l-dibromo-2.4.6-tri-tert-butyl-X -phosphorin was formed. 

The 4,7-dimethyl diquaternary salt of 4,7-phenanthroline is reduced in aqueous solution at a potential (E0) of —0.30 volt by a one-electron transfer to give a radical cation. The polarographic reduction of the salt has been studied in nonaqueous solvents.15,307 The electrochemical reduction of the salt has also been investigated.323 4,7-Phenanthroline 4,7-dimethiodide reacts with methyl magnesium iodide to give the expected 3,4,7,8-tetrahydro-3,4,7,8-tetramethyl-4,7-phenanthroline, which is unstable in air.284... 

Methyl hexyl carbinol may be made in a pure state by the action of methyl magnesium iodide upon heptaldehyde,1 but it is more easily and cheaply obtained in a state of satisfactory purity for most purposes by the heating of castor oil with sodium hydroxide.2 This gives sodium ricinoleate which upon fusion with caustic soda yields methyl hexyl carbinol. Other methods of theoretical interest have also appeared the product may be prepared by the chlorination and subsequent hydrolysis of petroleum octane 3 by the distillation of certain rarer oils with sodium hydroxide.4... 

Hematoporphyrin-IX (69) can also be obtained from (70) by treatment with methyl-magnesium iodide. 

Cydopentene oxide and 1 -methylcyclopentene oxide yield respectively Iran - 2 -methyloyclopentanol and a mixture of cie- and Iran 1.2-dixnethylcyclopentanol (Eq. 851) on treatment with methyl-magnesium iodide. 0 - . The latter could in principle be formed either by a preliminary isomerization to 2-methyJcyolopentanone, or by direct addition to the least-substituted epoxide carbon atom. These possibilities have not, however, been distinguished until now. 

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