精品视频中文字幕,国产精品偷伦视频免费观看了,人人干干

108-97-4
77 suppliers
$61.00/250mg

84302-42-1
17 suppliers
inquiry

-

Yield: 33%

Reaction Conditions:

with hydrogen;5% palladium/carbon hydrated in ethanol;toluene at 20; for 1 h;

Steps:

7 Example 7
Example 7 (Synthesis of dihydropyran-4-one) In a flask made of glass having an inner volume of 20 ml and equipped with a stirring device, a thermometer, a reflux condenser and a balloon filled with hydrogen were charged 3.0 g (31.2 mmol) of pyran-4-one, 0.6 g (50% hydrated product; containing 0.14 mmol as a palladium atom) of 5% by weight palladium/carbon, 30 ml of toluene and 3 ml of ethanol, and the mixture was reacted under hydrogen atmosphere at room temperature for 1 hour. After completion of the reaction, the reaction mixture was filtered, and the filtrate was concentrated. The concentrate was purified by silica gel column chromatography (Eluent; hexane:ethyl acetate=10:1) to give 1.0 g (Isolation yield; 33%) of dihydropyran-4-one as colorless liquid. Physical properties of dihydropyran-4-one are as follows. CI-MS (m/e); 99 (M+1) 1H-NMR (CDCl₃, δ (ppm)); 2.57 to 2.63 (2H, m), 4.50 (2H, dd, J=7.6Hz, 6.8Hz), 5.41 (1H, d, J=6.1Hz), 7.35 (1H, d, J=6.1Hz)

References:

Ube Industries, Ltd. EP1700853, 2006, A1 Location in patent:Page/Page column 13

29943-42-8 Synthesis