تفاعل #12042

معادلة التفاعل

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

المذيبات

diethyl ether

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter warming to −75 deg C
2. 2
   استخلاصextracted three times with ethyl acetate
3. 3
   غسيلThe combined organic layers were washed with brine
4. 4
   تجفيفdried over magnesium sulfate
5. 5
   ترشيحfiltered
6. 6
   أخرىevaporated
7. 7
   أخرىThe residue was chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (2:3) as eluant
8. 8
   أخرىto afford a first batch of compound
9. 9
   workup.ADDITIONThe remaining product-containing fractions
10. 10
    أخرىchromatographed again
11. 11
    أخرىto yield a second batch of compound (56.9% total)

الإجراء التجريبي

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).

المصدر