Allylmagnesium Chloride Research Articles

Unusual stereochemistry in the copper-catalysed ring opening of a carbohydrate oxirane with vinylmagnesium bromide

The oxirane ring of 4,6-O-benzylidene-1,5 : 2,3-dianhydrp-D-allitol (1) opened regio- and stereo-selectively at C-2 with Me2CuLi and allylmagnesium chloride in the presence of catalytic amounts of CuI. With vinylmagnesium bromide, however, the ring opening of (1) was regioselective but a mixture of stereoisomers (10) and (12) was obtained corresponding to retention and inversion at C-2. A mechanism for the formation of the anomolous retention product (12) is proposed.

A convenient preparative method of 2,3‐dialkyi parasorbic acids from carboxylic acids

AbstractVarious 2,3‐dialkyl parasorbic acids were prepared from carboxylic acids. For example, 2‐methyl‐5‐pentyI parasorbic acid was prepared from hexanoic acid and propanoic acid as follows: Grignard reaction of hexanoic acid (I) with allylmagnesium chloride gave l‐nonen‐4‐one (II) and the reaction of (II) with propanoic acid (III) with lithium naphthalenide in the presence of diethylamine produced 3‐allyl‐3‐hydroxy‐2‐methyloctanoic acid (IV). From the reaction of (IV) with 97% (v/v) sulphuric acid, 2‐methyl‐3‐pentyl parasorbic acid was formed. Several 2,3‐dialkyl parasorbic acids were obtained by this method. These products may be used as perfumery materials.

ChemInform Abstract: SYNTHESIS OF 2‐ALKYL‐3‐METHYL‐2‐CYCLOPENTENONES FROM CARBOXYLIC ACIDS OR METHYLKETONES

AbstractAuf zwei verschiedenen Wegen werden die Homoallylalkohole (III) aus Ketonen (I) bzw. (IV) mit den Grignardverbindungen (II) bzw. (V) hergestellt.

Syntheses of Allylketones, α, β-Unsaturated Ketones, and Methylketones from Carboxylic Acids

Various allylketones were prepared from carboxylic acids and allylmagnesium chloride. For example, the reaction of allylmagnesium chloride with hexanoic acid (1) gave 1-nonen-4-one (2). When these allylketones were treated with various acidic or basic catalysts, they were isomerised to the corresponding α, β-unsaturated ketones or methyl ketones. For example, tans-2-nonen-4-one (4) was obtained by the isomerisation of 1-nonen-4-one (2) with p-toluenesulphonic acid. By treating of 1-nonen-4-one (2) with 3 N sodium hydroxide solution, 2-heptanone (6) was obtained. These ketones can be used as starting materials for the synthesis of terpenes. For example, a new terpenic ketone, 3, 7-dimethyl-1-octen-5-one (10) was obtained from 6-methyl-trans-2-hepten-4-one (9) and vinylma gnesium chloride.

Synthesis of 2‐alkyl‐3‐methyl‐2‐cyclopentenones from carboxylic acids or methylketones

AbstractVarious 2‐alkyl‐3‐methyl‐2‐cyclopentenones were prepared via 2‐alkyl‐4‐penten‐2‐ols serving as common intermediates from carboxylic acids or methylketones. For example, dihydrojasmone was prepared from heptanoic acid as follows: Grignard reaction of heptanoic acid (I) with allylmagnesium chloride gave 1‐decen‐4‐one (II) and re‐Grignard reaction of (II) with methylmagnesium iodide produced 4‐methyl‐1‐decen‐4‐ol (IV). 4‐Methyl‐1,4‐decanediol (V) was obtained by hydroboration of (IV). Oxidation of (V) with chromium trioxide gave 4‐hexyl‐4‐methyl‐4‐butanolide (VI). Dihydrojasmone may be prepared by dehydration of (VI) with polyphosphoric acid. Several new 2‐alkyl‐3‐methyl‐2‐cylopentenones were obtained by this method.

A Preparative Method of Allylketones from Esters of Carboxylic Acids

Various allyl ketones were prepared from esters via two steps : Grignard reaction of allylmagnesium chloride with esters and thermolysis of the resulted diallyl alcohol. For example, 4-allyl-1-decen-4-ol (2) was prepared from methylheptanate (1) and allylmagnesium chloride. At 440°C and atmospheric pressure, compound (2) thermally decomposes to 1-decen-4-one (3).

Spectres de vibration et structures de composés allyliques du sodium, du lithium et du magnésium. Application à l'étude de l'allyllithium et du chlorure d'allylmagnésium en solution

Infrared and Raman spectra (4000-30 cm −1) of allylsodium C 3H 5Na, allyllithium C 3H 5 6Li and C 3H 5 7Li, diallylmagnesium (C 3H 5) 2Mg and allylmagnesium halides C 3H 5MgX, where X  Cl or Br, compounds in the solid state are reported. A complete assignment of allylic vibrations and of metal—allyl vibrations is proposed. These analyses are in agreement with a strong ionic character of these compounds; approximate metal—allyl force constants have been calculated. In addition, infrared spectra (1700-200 cm −1) of allyllithium and allylmagnesium chloride solutions in tetrahydrofuran and in ethyl ether are consistent with some ionic character of the species in solutions.

1,4-Addition of allylmagnesium chloride to 2-methylquinoline via 1,2-addition and subsequent rearrangement

1,4-Addition of allylmagnesium chloride to 2-methylquinoline via 1,2-addition and subsequent rearrangement

Reactions of some grignard reagents with 2,6-dichloropyridine

Reaction of benzylmagnesium chloride with 2,6-dichloropyridine gave 3-benzylglutarimide. Allylmagnesium chloride with 2,6-dichloropyridine, in a 1 1 molar ratio, gave 2-allyl-6-chloropyridine; and in a 2 1 molar ratio gave 2,6-diallylpyridine.

Reaction of poly(vinyl chloride) with magnesium and grignard reagents

AbstractReaction of poly(vinyl chloride) with magnesium under various conditions was attempted, but poly(vinyl chloride) did not react with magnesium. The reactions of poly(vinyl chloride) with benzylmagnesium chloride and allylmagnesium chloride as Grignard reagents were carried out in tetrahydrofuran at reflux temperature. It was found that the chlorine atoms in the poly(vinyl chloride) were replaced by benzyl and allyl groups by the coupling reaction, and a small amount of Grignard reagent of poly(vinyl chloride) was formed by the magnesium–halogen exchange reaction. The extent of the substitution increased with increasing reaction time and concentration of the Grignard reagent.

Reaction of polyepichlorohydrin with magnesium and grignard reagents

AbstractThe reaction of polyepichlorohydrin with magnesium in tetrahydrofuran at reflux temperature was studied in the hope of obtaining a polymeric Grignard reagent. The polymeric Grignard reagent could not be obtained, but dechlorination occurred. It was confirmed that the Grignard reagent of polyepichlorohydrin was formed as an intermediate during the dechlorination. The reactions of polyepichlorohydrin with Grignard reagents were carried out in tetrahydrofuran at reflux temperature. Benzylmagnesium chloride and allylmagnesium chloride were used as Grignard reagents. It was found that the chlorine atom in polyepichlorohydrin can be replaced by benzyl and allyl groups. The extent of the substitution increased with increasing concentration of Grignard reagent. Dechlorination and scission of the ether linkage occurred simultaneously as side reactions.

Transition metal–carbon bonds. Part XIX. Some Dewar hexamethylbenzene derivatives of rhodium(I)

Treatment of [Rh2Cl2(C2H4)4] with hexamethylbicyclo[2,2,0]hexa-2,5-diene (DHMB) gives a bridged chlorocomplex [Rh2Cl2(C12H18)2] in which the DHMB is acting as a chelating diolefin. [Rh2Cl2(C12H18)2] has been converted into [Rh2Br2(C12H18)2], [RhY(C12H18)](Y = acac or C5H5), and [RhClZ(C12H18)](Z = PPh3, AsPh3, or isoquinoline). With allylmagnesium chloride [Rh2Cl2(C12H18)2] gives [Rh(C3H5)3]. I.r. and n.m.r. data are discussed.

Diallyldicyclopentadienylzirconium and some related complexes

The complexes Cp 2Zr(C 3H 5) 2, Cp 2ZrCl(C 3H 5) (impure) and Cp 4Zr 2Cl(C 3H 5) 3 were prepared in crystalline form by reaction of Cp 2ZrCl 2 with allylmagnesium chloride in THF. In a similar way, the 2-methylallyl complexes Cp 2Zr(C 4H 7) 2 and Cp 2ZrCl(C 4H 7) were obtained as oils. The complexes are air sensitive. Infrared spectroscopy shows that the allylic ligands in Cp 2ZrCl(C 3H 5) and Cp 2ZrCl(C 4H 7) are σ-bonded to the metal, while in Cp 2Zr(C 3H 5) 2 and Cp 2Zr(C 4H 7) 2 one of the allylic ligands is π-bonded, the other σ-bonded. In Cp 4Zr 2Cl(C 3H 5) 3, which is probably a molecular complex, one allyl group is π-bonded, the other two σ-bonded. The NMR spectra of the allylic ligands are of the dynamic type. The bonding of the allylic ligands are their CC stretching frequencies are discussed and compared with corresponding titanium and vanadium complexes; it is found that substitution of the hydrogen atom at 2-C of the allyl group by a methyl group leads to an increase of the CC stretching frequency of σ-allylic ligands, but to a decrease in the case of π-allylic ligands.

The reaction of Grignard reagents with 2,2-dimethyl-2,3-dihydrophenalene-1,3-dione: addition and ring-opening reactions

The reaction of 2,2-dimethyl-2,3-dihydrophenalene-1,3-dione with methylmagnesium iodide, benzylmagnesium chloride, allylmagnesium chloride, and phenylethynylmagnesium iodide, under various conditions, has been examined and the products characterised.Fission of the alicyclic ring was observed with methylmagnesium iodide: this reaction cannot involve a cyclic chelated intermediate complex.

Synthesis of 1‐pentene‐4‐14C and 1‐pentene‐5‐14C

Abstract1‐Pentene‐4‐14C and 1‐pentene‐5‐14C were obtained in one single step from iodoethane‐1‐14C and iodoethane‐2‐14C, respectively, by reaction with allylmagnesium chloride in tetrahydrofurfuroxytetrahydropyran (TFTP) as solvent. The synthesis was carried out on a twenty mmoles scale in a completely closed apparatus. The pentenes were formed in 80 % yield. After final purification by means of gas‐liquid chromatography the radio‐chemical purity was 99.7 %.