反応 #1702034

反応方程式

HCl

diisopropylethylamine

acetyl bromide

5

3-Methoxydodecanal

AlMe3

→

6

収率 77.3%

(4R)-4-((2RS)-2-Methoxyundecyl)oxetan-2-one

収率 77.3%

溶媒

CH2Cl2

CH2Cl2

反応条件

後処理

1. 1
   温度cooled to −45° C.
2. 2
   workup.STIRRINGThe resulting pale yellow solution was stirred for 14 h at −45° C.
3. 3
   温度warmed to rt
4. 4
   workup.ADDITIONpoured into a separatory funnel
5. 5
   洗浄The organic layer was washed with saturated NaHCO3, brine
6. 6
   乾燥dried (Na2SO4)
7. 7
   その他The solvent was removed in vacuo
8. 8
   その他the yellow oily product was purified by chromatography on SiO2 (4% EtOAc/hexanes to 6% EtOAc/hexanes)

実験手順

A solution of N,N′-(1R,1′R)-1,1′-(benzylazanediyl)bis(2-methylpropane-1,1-diyl)bis(1,1,1-trifluoromethanesulfonamide) (81.2 mg, 0.15 mmol, 30 mol %) in CH2Cl2 (1 mL) was treated at rt under N2 slowly with a solution of AlMe3 (10.8 mg, 0.15 mmol) in CH2Cl2 (0.5 mL). The mixture was stirred at room temperature (rt) for 2 h, cooled to −45° C. and treated sequentially with diisopropylethylamine (11 mg, 1.7 equiv), acetyl bromide (117 mg, 1.9 equiv) and 5 (107 mg, 0.500 mmol, 1.0 equiv). The resulting pale yellow solution was stirred for 14 h at −45° C., warmed to rt, and poured into a separatory funnel containing 0.1 N HCl (10) mL). The organic layer was washed with saturated NaHCO3, brine, and dried (Na2SO4). The solvent was removed in vacuo and the yellow oily product was purified by chromatography on SiO2 (4% EtOAc/hexanes to 6% EtOAc/hexanes) to give 6 (99.1 mg, 77%) as a colorless oil: 1H NMR (CDCl3) 4.8-4.65 (m, 1H), 3.60-3.50 (m, 1H), 3.3-3.2 (m, 1H), 3.35, 3.32 (2s, 3H), 3.22-3.08 (m, 1H), 2.18-1.82 (m, 2H) 1.65-1.35 (m, 2H), 1.35-1.20 (m, 14H), 0.90-0.80 (m, 3H).

出典