反応 #12042

反応方程式

ammonium chloride

tert-butyllithium

(4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

acetaldehyde

→

(4R,9aR)-6-(1-(RS)-Hydroxy-ethyl)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

溶媒

diethyl ether

反応条件

後処理

1. 1
   温度After warming to −75 deg C
2. 2
   抽出extracted three times with ethyl acetate
3. 3
   洗浄The combined organic layers were washed with brine
4. 4
   乾燥dried over magnesium sulfate
5. 5
   ろ過filtered
6. 6
   その他evaporated
7. 7
   その他The residue was chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (2:3) as eluant
8. 8
   その他to afford a first batch of compound
9. 9
   workup.ADDITIONThe remaining product-containing fractions
10. 10
    その他chromatographed again
11. 11
    その他to yield a second batch of compound (56.9% total)

実験手順

A solution of 6.0 g (16.3 mmol) (4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester in 250 ml diethyl ether was cooled to −100 deg C. and treated with 11.9 ml (17.9 mmol) tert-butyllithium (1.5 M in n-pentane). After 15 min, 1.0 ml (0.79 g, 17.9 mmol) acetaldehyde was added and the reaction was stirred for 40 min at the same temperature. After warming to −75 deg C. the reaction mixture was poured onto 10% aqueous ammonium chloride solution and extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (2:3) as eluant to afford a first batch of compound. The remaining product-containing fractions were pooled and chromatographed again to yield a second batch of compound (56.9% total).

出典