1941年在猫薄荷中分离出荆芥内酯(JACS.1941.63.1558),67-80%猫猫会对其起反应
合成路线如下:
(绘图软件:Chemdraw)
Step 1.二氧化硒氧化氧化烯丙基位的C-H得到烯丙醇产物
反应机理
[2,3]σ重排(Ref: J. Org. Chem. 2000 , 65 , 7554., Tetrahedron Lett. 2003 , 44 , 1099.)
虽然这试剂是有毒的,但是该反应非它不可,条件也很温和所以经常还是在被使用。如果加入助氧化剂TBHP的话,可以把二氧化硒的使用量减少到催化量。
step1.
操作步骤:
Racemic citronellol (23.4 mL, 128 mmol, 1 eq) was added to a solution of SeO2 (0.855 g, 7.7 mmol, 0.06 eq), salicylic acid (2.13 g, 15.4 mmol, 0.12 eq), and t-BuOOH (70% in H2O, 53 mL, 553 mmol, 4.3 eq) in DCM (40 mL) and the resulting reaction mixture was stirred at rt for 72 h. The reaction mixture was diluted with toluene (100 mL) and the volatiles were removed by rotary evaporation. The residue was diluted with ether (400 mL) and washed with NaOH (10% w/v, 4 × 140 mL) and brine (1 × 120 mL). The organic layer was dried over MgSO4 (anhyd), filtered, and the volatiles were removed by rotary evaporation to yield a clear yellow oil (21.2 g, 95%).
原料香茅醛
Racemic citronellol (23.4 mL, 128 mmol, 1 eq)in DCM (40 mL)
SeO2 (0.855 g, 7.7 mmol, 0.06 eq)& salicylic acid (2.13 g, 15.4 mmol, 0.12 eq)
t-BuOOH (70% in H2O, 53 mL, 553 mmol, 4.3 eq)
The mixture was stirred at r.t. for 72 h
After 3 days,analysis of the reaction mixture by TLC(Hexane:ethyl acetate=5/1)
step 2.戴斯-马丁氧化
the reaction mixture was diluted with toluene (100 mL) and the volatiles were removed by rotary evaporation. The residue was diluted with ether (400 mL) and washed with NaOH (10% w/v, 4 × 140 mL) and brine (1 × 120 mL). The organic layer was dried over MgSO4 (anhyd), filtered, and the volatiles were removed by rotary evaporation to yield a clear yellow oil。Then Dess-Martin periodinane was added to a solution of this product in DCM and the resulting reaction mixture was stirred at 0℃ overnght。