反应 #1884983

反应方程式

isopropyl 2(S)-(tert-butoxycarbonylamino)-5-hydroxypentanoate

allyl methyl carbonate

BINAP

ether hexane

→

isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate

溶剂

ether

THF

反应条件

后处理

1. 1
   温度was refluxed under nitrogen for 3 hours
2. 2
   过滤filtered through celite
3. 3
   其他evaporated
4. 4
   其他giving a dark brown syrup

实验过程

A degassed mixture of isopropyl 2(S)-(tert-butoxycarbonylamino)-5-hydroxypentanoate (product of step 26C, 17.6 g, 63.9 mmol), allyl methyl carbonate (24.0 ml, 213 mmol), Pd2(dba)3 (1.62 g, 1.78 mmol) and BINAP (4.42 g, 7.10 mmol) in THF (150 mL) was refluxed under nitrogen for 3 hours. After cooling to room temperature, the reaction was diluted with ether, filtered through celite and evaporated giving a dark brown syrup. Flash chromatography of the residue (silica gel, 30% ether/hexane) gave isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate as a viscous colorless oil, 16.3 g (81%): 1H NMR (300 MHz, Chloroform-D) δ 5.88 (ddt, 1 H, 17.4, 10.4, 5.5), 5.28 (m, 1 H), 5.22-5.11 (m, 1 H), 5.02 (sept., 1 H, J=6.2 Hz), 4.21 (br t, 1 H, J=6.7 Hz), 3.94 (dt, 2 H, J=5.9, 1.5 Hz), 3.42 (t, 2 H, J=5.9 Hz), 1.90-1.82 (m, 1 H), 1.75-1.57 (m, 3 H), 1.42 (s, 9 H), 1.21 (d, 3 H, J=6.2 Hz), 1.19 (d, 3 H, J=6.2 Hz). LCMS m/z 316 (M+H)+.

来源