反応 #2659

反応方程式

trityl chloride

1,8-diazabicyclo[5.4.0]undec-7-ene

4-hydroxy-2-cyclopentenone

→

title compound

収率 37.0%

4-trityloxy-2-cyclopentenone

収率 37.0%

溶媒

methylene chloride

反応条件

後処理

1. 1
   workup.ADDITIONpoured onto ice (approximately 25 mL)
2. 2
   その他The phases are separated
3. 3
   洗浄the organic phase is washed with water (25 mL)
4. 4
   乾燥The organic phase is dried over anhydrous magnesium sulfate
5. 5
   ろ過filtered
6. 6
   濃縮concentrated under vacuum
7. 7
   その他The residue is purified by column chromatography (silica gel, 10-20% ethyl acetate/hexane)

実験手順

A solution of trityl chloride (3.44 g, 12.3 mmol) in methylene chloride (20 mL) is treated sequentially with 1,8-diazabicyclo[5.4.0]undec-7-ene (2.2 mL, 14.7 mmol, DBU) and 4-hydroxy-2-cyclopentenone (1.01 g, 10.0 mmol, in 5 mL of methylene chloride, prepared in example 1). The reaction is stirred for 3 days at room temperature and then poured onto ice (approximately 25 mL). The phases are separated and the organic phase is washed with water (25 mL). The organic phase is dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue is purified by column chromatography (silica gel, 10-20% ethyl acetate/hexane) to provide the title compound (1.26 g, 36%) as a pale yellow oil; 1H NMR (CDCl3) δ7.5 (m, 6H), 7.3 (m, 9H), 6.85 (dd, 1H), 6.05 (d, 1H), 4.8 (m, 1H), 2.1 (m, 2H); 13C NMR (CDCl3) δ206.6, 162.9, 144.3, 135.2, 128.8, 128.4, 127.7, 88.2, 73.1, 43.4; IR (KBr) νmax 3061, 1719, 1491, 1449, 1352, 1181, 1107, 1053 cm-1.

出典