In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 3618-04-0, name is trans-Ethyl 4-hydroxycyclohexanecarboxylate belongs to esters-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below. Formula: C9H16O3
To a solution of ethyl 4-hydroxycyclohexanecarboxylate 2 (mixture of cis and trans) (2.5 g, 14.5 mmol) and imidazole (1.97 g, 29 mmol) in anhydrous DMF (20 mL), tert-butyldimethylsilyl chloride (2.63 g, 17.5 mmol) was added. After stirring overnight, Et2O (60 mL) and 1M aqueous HCl (60 mL) were added. After extraction with Et2O, the combined organic phases were washed with 1M aqueous HCl and brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give a TBS-protected alcohol as a colorless oil (4.14 g), which was used in the next step without further purification. To a solution of the former alcohol (4.14 g, 14.5 mmol) in THF (20 mL) and methanol (12 mL), lithium hydroxide (0.7 g, 29 mmol) was added. The mixture was then stirred at 60 C for 3 h. After removal of the solvents, water and Et2O were added and the aqueous layer was extracted with diethyl ether, cooled in an ice bath then acidified to pH=1 with 1M aqueous HCl. After extraction with ethyl acetate, the organic phases were dried over Na2SO4, filtered and concentrated. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate, 50:50) to give the title compound 3 as a mixture of cis/trans isomers (3.48 g, 100% yield) as a colorless oil; deltaH (400 MHz, CDCl3) 10.84 (2H, m, 2*COOH), 3.89 and 3.56 (2*1H, 2*bs, 2*H-4), 2.41-2.18 (2H, m, 2*H-1), 2.10-1.83 (6H, m), 1.74-1.59 (4H, m), 1.58-1.23 (6H, m), 0.88 and 0.87 (2*9H, 2*s, 2*(CH3)3CSi), 0.05 and 0.03 (2*6H, 2*s, 2*(CH3)2Si); deltaC (100 MHz; CDCl3) 181.8 (2*COOH), 70.5 and 66.7 (2*C-4), 42.0 and 41.9 (2*C-1), 34.8 (2*CH2), 32.9 (2*CH2), 27.1 (2*CH2), 23.4 (2*CH2), 26.1 and 26.0 (2*(CH3)3CSi), 18.3 and 18.2 (2*(CH3)3CSi), -4.5 and -4.7 (2*(CH3)2Si).
The synthetic route of 3618-04-0 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Zeinyeh, Wael; Radix, Sylvie; Terreux, Raphael; Chemelle, Julie-Anne; Walchshofer, Nadia; Tetrahedron; vol. 72; 27-28; (2016); p. 4032 – 4038;,
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