反应详情

To a 500-mL three-necked round-bottom flask equipped with an overhead mechanical stirrer was charged 3-(3-quinolyl)-2-propen-1-ol (13.03 g, 70.43 mmol) as a mixture of cis- and trans-isomers (81% cis, and 19% trans), di-tert butyl dicarbonate (16.91 g, 77.48 mmol, 1.11 equiv), tetra n-butylammonium hydrogen sulfate (742 mg, 2.17 mmol) and methylene chloride (135 mL). The stirred mixture which resulted was cooled to 0 to 5° C. at which time aqueous 25% sodium hydroxide (33.3 mL) was added over 45 minutes such that the internal temperature did not rise above 20° C. Upon completion of the reaction (1 to 4 hours) as indicated by TLC (3:2 ethyl acetate/heptane), the reaction mixture was diluted with methylene chloride (50 mL) and washed with water (2×125 mL). The organic was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo to provide the 3-(3-quinolyl)-2-propen-1-ol-t-butyl carbonate: 18.35 g, 91.4% as an oil. This material can be further purified to remove lower Rf impurities by eluting through a plug of silica gel with heptane/acetone/triethylamine (9:1:0.1). The product eluant is then concentrated under reduced pressure and further dried by the azeodistillation of ethyl acetate. This procedure provides the purified carbonate as a colorless oil which retains the original ratio of cis and trans isomers: 17.50 g, 87.2%.

1. customTo a 500-mL three-necked round-bottom flask equipped with an overhead mechanical stirrer
2. customThe stirred mixture which resulted
3. additionwas added over 45 minutes such that the internal temperature
4. customdid not rise above 20° C
5. customUpon completion of the reaction (1 to 4 hours)
6. washwashed with water (2×125 mL)
7. dry with materialThe organic was dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo