2H-PYRAN-3(4H)-ONE, DIHYDRO-

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Cyclohexylamine (3.43 ml, 30.0 mmol) was added to pyran-3-one (3000 mg, 30.0 mmol) in benzene (20 mL). The reaction mixture was stirred at RT for 30 min and then refluxed for 2 hr with a dean-stark trap. The benzene was then distilled off and the residue was redissolved in THF (2 mL) and added to BuLi (13.18 ml, 33.0 mmol) in THF (Volume: 30.000 ml) at 0° C. The reaction mixture was stirred at 0° C. for 1 h before 5-bromo-1-pentene (5582 mg, 37.5 mmol) was added. The reaction mixture was stirred at 0° C. for 2 hr. The mixture was cooled and quenched with water. The reaction mixture was extracted with diethyl ether (3×20 mL). The combined organic fractions were washed with water and brine (saturated, 100 mL), dried, filtered and the solvent was evaporated under reduced pressure (400 mmhg). The residue was purified by column chromatography on silica gel to provide the title compound. 1H NMR (500 MHz, CDCl3) δ 5.74-5.86 (m, 1H), 4.92-5.06 (m, 2H), 3.90-4.06 (m, 3H), 3.77-3.85 (m, 1H), 2.41-2.49 (m, 1H), 2.16-2.24 (m, 1H), 2.01-2.12 (m, 2H), 1.72-1.97 (m, 2H), 1.31-1.49 (m, 3H). refluxed for 2 hr with a dean-stark trap The benzene was then distilled off the residue was redissolved in THF (2 mL) was added The reaction mixture was stirred at 0° C. for 2 hr The mixture was cooled quenched with water The reaction mixture was extracted with diethyl ether (3×20 mL) The combined organic fractions were washed with water and brine (saturated, 100 mL) dried filtered the solvent was evaporated under reduced pressure (400 mmhg) The residue was purified by column chromatography on silica gel