5382-77-4

96835-17-5

General procedure for the synthesis of ethyl tetrahydropyran-4-carboxylate from diethyl dihydro-2H-pyran-4,4(3H)-dicarboxylate: 1. Diethyl dihydro-2H-pyran-4,4(3H)-dicarboxylate (400 mg, 1.74 mmol) was dissolved in N,N-dimethylformamide (4 ml), and lithium iodide (1.16 g, 8.66 mmol) and sodium cyanide (94 mg, 1.91 mmol) were added in sequence. ) and sodium cyanide (94 mg, 1.91 mmol). The reaction mixture was heated at 130 °C for 7 h, followed by heating up to 140 °C for a further 25 h. The reaction mixture was then heated up to 140 °C for a further 25 h. The reaction was confirmed to be more than 95% complete by GC analysis. Upon completion of the reaction, the mixture was partitioned between 33% diethyl ether/hexane (100 ml) and brine (25 ml). The organic layer was washed with additional brine (25 ml), dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give ethyl tetrahydropyran-4-carboxylate (253 mg, 92% yield).