반응 #66340

반응 방정식

benzyl alcohol

Hünig's base

2-(tert-butyldimethylsilyloxy)-2-(ethoxycarbonyl)cyclopropanecarboxylic acid

DPPA

→

title compound

수율 32.0%

Ethyl-2-(Benzyloxycarbonylamino)-1-(tert -butyldimethylsilyloxy)cyclopropanecarboxylate

수율 32.0%

용매

ethyl acetate

toluene

반응 조건

후처리

1. 1
   온도the mixture was heated at 90° C. for 30 min
2. 2
   온도the mixture was cooled
3. 3
   세척washed sequentially with 10% citric acid (2×50 mL), water (50 mL), and saturated NaHCO3 (50 mL)
4. 4
   건조The organic phase was dried (MgSO4)
5. 5
   여과filtered
6. 6
   농축concentrated
7. 7
   기타The residue was purified by silica gel chromatography
8. 8
   세척eluting with 10% EtOAc/hexanes to 100% EtOAc

실험 절차

A mixture of 2-(tert-butyldimethylsilyloxy)-2-(ethoxycarbonyl)cyclopropanecarboxylic acid (4b, 0.335 g, 1.16 mmol) in toluene (5 mL) under nitrogen was treated with Hünig's base (0.260 mL, 1.51 mmol) and the mixture was cooled to 0° C. After this time, DPPA (0.324 mL, 1.51 mmol) was added and the mixture was heated at 90° C. for 30 min, followed by the addition of benzyl alcohol (0.155 mL, 1.51 mmol). After 15 h, the mixture was cooled, diluted with ethyl acetate (75 mL), and washed sequentially with 10% citric acid (2×50 mL), water (50 mL), and saturated NaHCO3 (50 mL). The organic phase was dried (MgSO4), filtered, and concentrated. The residue was purified by silica gel chromatography eluting with 10% EtOAc/hexanes to 100% EtOAc to afford the title compound as a clear oil (0.146 g, 30%): 1H NMR (300 MHz, CDCl3) δ 7.34-7.30 (m, 5 H), 5.40-5.38 (m, 1H), 5.21-5.00 (m, 2H), 4.29-4.18 (m, 2H), 4.16-4.09 (m, 1H), 1.50-1.47 (m, 2H), 1.30 (t, J=7.2 Hz, 3H), 0.88 (s, 9H), 0.26-0.07 (m, 6H); Multimode (APCI+ESI) MS m/z 295 [M+H]+.

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