Bailey, William J.; Barclay, Robert Jr. published the artcile< Cyclic dienes. XXIII. 1,4-Dimethylene-2-cyclohexene>, Safety of (9Z,12Z)-Methyl octadeca-9,12-dienoate, the main research area is .
p-C6H4(CO2Me)2 (I) (643 g.), 40 cc. absolute EtOH, and 36 g. W-2 Raney Ni hydrogenated 1.8 hrs. at 140-85°/3 atm., the mixture dissolved in hot EtOH and filtered, the filtrate cooled overnight at about 5° and filtered from 48 g. unchanged I, and the final filtrate distilled gave 54 g. forerun, b7 68-119°, and 512 g. di-Me cis- and trans-1,4-cyclohexanedicarboxylate (II), b6-7 122.5-6.5°, n31D 1.4560; the forerun refractionated yielded 15 g. impure Me 4-methylcyclohexanecarboxylate, b3.0 50-8.5°, n25D 1.4490, 26 g. (crude) p-MeC6H4CO2Me (III), b3.7-4.0 77-80°, n25D 1.5120, m. 32-5°, and 11 g. impure II, b3.6-3.8 104.5-17.5°, n25D 1.4579. The III (4.7 g.) saponified gave 3.12 g. p-MeC6H4CO2H, m. 180-1°. II (522 g.), 200 cc. H2O, and 4500 cc. MeOH treated with stirring during 7.5 hrs. with 121 g. KOH in 300 cc. H2O, stirred 13.5 hrs., concentrated with the removal of about 4000 cc. solvent, the residue diluted with 1300 cc. H2O and extracted with Et2O, and the extract evaporated on the steam bath in a stream of air gave 165 g. unreacted II; the aqueous phase cooled to 15°, acidified with 180 cc. concentrated HCl, and extracted with 1100 cc. Et2O, and the extract worked up gave 310 g. mono-Me ester (IV) of cis- and trans-1,4-cyclohexanedicarboxylic acid. IV (380 g.) and 450 cc. SOCl2, b. 75.8°, heated during 2.2 hrs. to 87°, heated 1.75 hrs. at 87-96°, treated during about 8 hrs. with 110 cc. Br at 96-103°, stirred 9 hrs. at 100-5°, cooled, and evaporated in vacuo, the residue added during 28 min. to 300 cc. absolute MeOH, refluxed 1 hr., cooled, poured into about 2 l. H2O, and extracted with Et2O, and the extract worked up yielded 520 g. 1-Br derivative (V) of IV, b0.12-0.25 92.5-99°, n25D 1.4914. Crude V (553 g.) added during 6.3 hrs. with stirring to 528 g. KOH pellets in 1500 cc. MeOH at reflux temperature, refluxed an addnl. 50 min., kept overnight, about 700 cc. solvent removed in vacuo, the pasty residue dissolved in 2 l. H2O, and the solution acidified with 800 cc. concentrated HCl, cooled to about 27°, and filtered yielded 250 g. crude 1-cyclohexene-1,4-dicarboxylic acid (VI). Crude VI, 240 cc. SOCl2, and 300 cc. CHCl3 refluxed 5.8 hrs., cooled, diluted during 40 min. with 300 cc. absolute MeOH, heated, diluted with 10 cc. concentrated H2SO4 in 200 cc. absolute MeOH, refluxed 11 hrs., cooled, and poured into 1.5 l. H2O, and the product isolated with CHCl3 yielded 233 g. semisolid product which recrystallized from 500 cc. petr. ether gave 208 g. di-Me ester (VII) of VI, m. 34-6°. VII (220 g.) in 600 cc. dry Et2O added during 6 hrs. to 62 g. LiAlH4 in 1800 cc. dry Et2O, heated 58 hrs., and worked up yielded 142 g. impure 1-cyclohexene-1,4-dimethanol (VIII), b3.2-3.8 115-48°. The crude VIII in 65 cc. AcOH added during 55 min. to 525 cc. refluxing Ac2O, refluxed 9.4 hrs., and distilled gave 177 g. mixed acetate, b3.5-3.7 115.5-39°; the acetate mixture reduced with 40 g. LiAlH4 and acetylated with 426 cc. Ac2O and 55 cc. AcOH yielded 154 g. diacetate (IX) of VIII, b3.0 133-3.5°. IX (21.1 g.) pyrolyzed at 490-5° over Pyrex helices, the pyrolyzate washed several times with H2O, combined with the product from 2 parallel batches, and distilled gave 13.0 g. 1,4-dimethylene-2-cyclohexene (X), b47 57°, n25D 1.5398, 8.8 g. mixture of diene acetates, b3.0-3.2 73.5-9.5°, n25D 1.4795, and 5.6 g. mixture of olefin diacetates, b3.0-3.3 128.5-36°. X (2.72 g.), 0.20 g. 10% Pd-C, and 0.19 g. hydroquinone heated during 2.25 hrs. from 135 to 180°, kept 10.75 hrs. at 174-80°, cooled somewhat, and distilled, and the distillate collected in 2 Dry Ice traps gave 0.79 g. crude p-xylene, n24D 1.4890, m. 5.3-11.2° (trinitro derivative m. 137.5-41°). X (1.08 g.) in 100 cc. EtOAc ozonized at 0° with O containing 0.0013 mole O3/l. during 8 hrs. at 6.8 l./hr. and the effluent passed through H2O gave from the aqueous solution the dimedon derivative of CH2O, m. 190.5-1.5°; the mixture evaporated, the residual ozonide heated 5 hrs. with 25 cc. 30% H2O2 and 40 cc. glacial AcOH on the steam bath, the solution stirred 40 hrs. while being heated, diluted at intervals with H2O to maintain the volume, and evaporated at atm. pressure, the gummy residue extracted with aqueous Me2CO, and the extract worked up gave 0.32 g. (CH2CO2H)2, m. 179-83°; N,N’-bis(p-tolylsuccinamide) m. 255.5-9.5°. X (0.48 g.), 0.0077 g. Bz2O2, and 7 cc. C6H6 refluxed 46 hrs., an addnl. 0.0303 g. Bz2O2 added in 4 portions during the heating, filtered, poured slowly into 100 cc. MeOH, treated with a small amount of 2-C10H7NHPh, allowed to stand 3 days, and filtered, and the residual polymer washed with MeOH and dried 2 days at about 2 mm. yielded 0.018 g. polymeric X, softens at about 150-5°. X (0.45 g.) and 5 cc. CS2 treated at -78° with BF3, kept 19.5 hrs. at -78° with occasional shaking, diluted with 1 cc. cold MeOH, warmed with stirring to room temperature, poured into 55 cc. MeOH, and filtered, and the residue washed with MeOH, and dried 36 hrs. at about 2 mm. gave 0.08 g. polymeric X.
Journal of the American Chemical Society published new progress about Unsaturated compounds. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Safety of (9Z,12Z)-Methyl octadeca-9,12-dienoate.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics