Liu, Yu-Cheng published the artcileFree radical reaction. Reaction of Grignard reagents with 2-bromo-2,3-dimethylbutane and with 1-chloro-1-methylcyclohexane in the presence of cobaltous halides, Application In Synthesis of 594-81-0, the publication is Acta Chim. Sinica (1956), 104-11, database is CAplus.
cf. C.A. 51, 14569e. CHMe2CBrMe2 (I) decomp, when treated with PhMgBr (II) and CoBr2 (III) to give 35% CHMe2CHMe2 (IV), 31% CHMe2CMe:CH2 (V), and 2% CMe2:CMe2 (VI). I (0.45 mole) added dropwise to 0.5 mole freshly prepared II in 250 ml. Et2O containing III with stirring, stirred with cooling several hrs., the product poured into ice H2O, 30 ml. AcOH added, the Et2O layer separated, washed neutral, dried, and fractionally distilled to 80° gave 25.8 g. fraction, b. 53-8°, n20D 1.3822, containing some V (infrared spectrum), mainly IV as shown by oxidation with O3 in CCl4 at 0° to CH2O (IV derivative with saturated 5,5-dimethyldihydroresorcinol, m. 192-3°) and some Me2CHCOMe; 2,4-(O2N)2C6H3NHNH2 derivative, m. 114-15°. The fraction b. 71.5° (0.7 g.) proved to be VI, m. 165° (sublimation). The residue gave 33 g. biphenyl, m. 70-2°, on steam-distillation Treatment of 9.7 g. I with 11.2 g. KOH in 50 ml. glycol at 100-10° 1.5 hrs. gave 4.1 g. distillate, n20D 1.4076, a mixture of 79% VI and 21% V. Bromination of 0.5 g. of this mixture in CCl4 yielded 61% CBrMe2CBrMe2, m. 170-5°. 1-Methylcyclohexyl chloride (VII) (0.2 mole) in 100 ml. absolute Et2O added dropwise to 0.3 moles MeMgBr (VIII) in 320 ml. Et2O with frequent addition (6.5 g. total) of III and stirring continued an addnl. hr. after complete evolution of the gas gave as the main distillate, b. 100-3°, n20D 1.4371, 62% mixture of C6H11Me, 1-methylcyclohexene (IX), and methylenecyclohexane. The % unsaturation of bromate-bromide titration and catalytic hydrogenation with Pt was 51, infrared absorption spectrum showed the presence of C:CH, and group oxidation with O3 gave cyclohexanone; 2,4-dinitrophenylhydrazone, m. 158.5-9.5°. VII (26.5 g.) in 40 ml. absolute Et2O with 0.4 mole iso-PrMgBr in 200 ml. Et2O in the presence of 2.6 g. III in the same way as above gave 11.3 g. distillate, b. 100-3°, n20D 1.4348, % unsaturation = 42, a mixture of the same products as from VII and VIII. VII (5 g.) and 25 ml. 4N NaOH refluxed on a steam-bath 3 hrs., extracted with Et2O, and distilled, gave 2.4 g. IX, b. 107-8°, n20D 1.4364. It is therefore suggested the disproportionation of alkyl radicals in solution is probably a bimol. reaction and the number of α-H atoms has a directive influence upon the orientation of olefin formation.
Acta Chim. Sinica published new progress about 594-81-0. 594-81-0 belongs to bromides-buliding-blocks, auxiliary class Bromide,Aliphatic hydrocarbon chain, name is 2,3-Dibromo-2,3-dimethylbutane, and the molecular formula is C6H12Br2, Application In Synthesis of 594-81-0.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary