3,4-dihydro-2H-pyran → Tetrahydropyranyl ether

A mixture of 2.65 g of (1R,5S,6R,7R)-6- ethoxycarbonyl-3,3-ethylenedioxy-7-hydroxybicyclo[3.3.0]octane (IX), 1.34 g of dihydropyrane, 0.26 g of pyridinium p-toluenesulfonate in 30 ml of anhydrous methylene chloride was stirred at room temperature for 3 hours. Then, the reaction mixture was successively washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine, dried over sodium sulfate, and concentrated to obtain as the residue 3.70 g of oily tetrahydropyranyl ether. A solution of the resulted crude tetrahydropyranyl ether in 15 ml of anhydrous diethyl ether was added dropwise over 1 hour to a stired and ice-cooled suspension of 0.59 g of lithium aluminum hydride in 50 ml of anhydrous diethyl ether. The mixture was further stirred at room temperature for 30 minutes. After ice-cooling, to the reaction mixture was added successively 0.6 ml of water, 1.8 ml of 10% aqueous sodium hydroxide solution and 0.6 ml of water, and the mixture was further stirred for 1 hour. The mixture was filtered through Celite, dried over sodium sulfate, and concentrated. The residue was purified by silica gel chromatography (eluting solution: 25% (v/v) ethyl acetate/hexane) to obtain 3.04 g of the oily title compound.

1. washThen, the reaction mixture was successively washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine
2. dry with materialdried over sodium sulfate
3. concentrationconcentrated

ORD record

ord-191d4d06db8a45d084fc73bf06839980

Source dataset

uspto-grants-1989_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04871869