反应详情

1.1 g of methyl trans-4-hydroxycyclohexanecarboxylate (6.95 mmol, 1.35 eq.), 1 g of tert-butyl 4-hydroxybenzoate (5.15 mmol, 1 eq.) and 2.03 g of triphenylphosphine (7.72 mmol, 1.5 eq.) are placed in 10 mL of tetrahydrofuran at room temperature. 1.5 mL of diisopropyl azodicarboxylate (7.72 mmol, 1.5 eq.) are added dropwise to the reaction medium with stirring. After 18 hours at room temperature, the medium is concentrated to dryness and taken up in diethyl ether. The triphenylphosphine oxide is filtered off. The organic phase is washed with sodium hydroxide solution, dried over sodium sulfate, filtered and evaporated to give a residue. This residue is chromatographed on silica gel, eluting with a gradient of ethyl acetate in heptane ranging from 0% to 50%. 1.23 g of tert-butyl cis-4-(4-methoxycarbonylcyclohexyloxy)-benzoate are obtained.

1. concentrationthe medium is concentrated to dryness
2. filtrationThe triphenylphosphine oxide is filtered off
3. washThe organic phase is washed with sodium hydroxide solution
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. customevaporated
7. customto give a residue
8. customThis residue is chromatographed on silica gel
9. washeluting with a gradient of ethyl acetate in heptane ranging from 0% to 50%