Production of 1,2-Cyclohexanedicarboxylates from Diacetone Alcohol and Fumarates

Abstract

1,2-Cyclohexanedicarboxylates, which are one of the most commonly used plasticizers in the poly(vinyl chloride) (PVC) industry, are generally prepared via the oxidation/esterification/hydrogenation of o-xylene (or naphthalene). Herein, we develop an alternative route toward cyclohexane-based plasticizers using diacetone alcohol and fumarates as the starting materials. The process includes a mild Raney Ni-catalyzed hydrogenation of diacetone alcohol, an one-step dehydration/Diels−Alder reaction of resulting 2methyl-2,4-pentandiol and fumarates in a choline chloride (ChCl) based deep eutectic solvent (DES), and a further Pd/ C-catalyzed hydrogenation. The toxicological tests indicate that the as-synthesized di(2-ethylhexyl) 3,5-dimethylcyclohexane-1,2-dicarboxylate can serve as a safe plasticizer for PVC materials.

Acid-catalyzed chemoselective C- and O- prenylation of cyclic 1,3-diketones

“…Other heterogeneous acids, such as H-MOR (Si/Al = 24) and H-USY (Si/Al = 3), showed no catalytic activity, while Amberlyst-15 was able to promote the annulation, albeit with decreased yield (entries 2-4). Temperature-programmed desorption of ammonia (NH3-TPD) experiments revealed the sequence of acid amount of the catalysts as Amberlyst-15 (3.397 mmol/g) > H-USY (1.318 mmol/g) > H-MOR (0.876 mmol/g), which is consistent with their catalytic performances [40]. An exception to this sequence was Nafion (2.123 mmol/g), which gave the highest yield of 3a (entry 1), presumably due to the strong, electron-deficient polyfluoro-substituted sulfonic group on Nafion making it more acidic than Amberlyst-15.…”

Diels–Alder Cycloaddition Reactions in Sustainable Media

“…Compound 68 and analogous derivatives could be further hydrogenated to give compounds that can serve as safe plasticizers for PVC materials. The synthesis of 3,5-dimethylcyclohex-4-ene-1,2-dicarboxylates using a ChCl-based DES medium has been reported [71]. The methodology involves a Raney Ni-catalyzed hydrogenation of diacetone alcohol 64 followed by a one-step dehydration/Diels-Alder reaction of the resulting 2-methylpentane-2,4-diol 65 and diethyl fumarate (67) in a ChCl/EG deep eutectic mixture, catalyzed by Amberlyst-15, leading to the formation of compound 68 as a single product (Scheme 15).…”

Synthesis of renewable alkylated decalins with p-quinone and 2-methyl-2,4-pentanediol

“…4,5 2-Methyl-2,4-pentanediol (MPD) is the hydrogenation product of diacetone alcohol (DAA) that can be obtained by the self-aldol condensation of acetone 6 from the acetone-butanolethanol (ABE) fermentation of cellulose and hemicellulose. 7 In the previous work of our group, 8,9 MPD was obtained at high yields ($100%) from the hydrogenation of DAA over commercial Ru/C and RANEY® Ni catalysts, respectively. p-Quinone is an unsaturated diketone that can be produced by the oxidation of aniline 10 or phenols 11,12 from lignin.…”