تفاعل #163415

معادلة التفاعل

6-oxaspiro[4.5]decan-9-one

methylcyanoacetate

ammonium acetate

acetic acid

→

methyl 2-cyano-2-[6-oxaspiro[4.5]decan-9-ylidene]acetate

المردود 87.8%

المذيبات

hexane

benzene

EtOAc

benzene

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas heated
2. 2
   درجة الحرارةat reflux in a 250 ml round bottom flask
3. 3
   أخرىequipped with a Dean-Stark and a reflux condenser
4. 4
   درجة الحرارةAfter cooling
5. 5
   أخرىthe layer was separated
6. 6
   غسيلthe organic was washed by water (120 ml)
7. 7
   استخلاصthe aqueous layer was extracted by CH2Cl2 (3×120 ml)
8. 8
   غسيلThe combined organic was washed with sat'd NaHCO3, brine
9. 9
   أخرىdried
10. 10
    تركيزconcentrated
11. 11
    أخرىthe residual was purified by flash chromatography (340 g silica gel column, eluted by EtOAc in hexane: 5% EtOAc, 2 CV; 5-25%, 14 CV; 25-40%, 8 CV)
12. 12
    أخرىgave
13. 13
    workup.ADDITIONa mixture of E and Z isomers

الإجراء التجريبي

A mixture of 6-oxaspiro[4.5]decan-9-one (13.74 g, 89.1 mmol), methylcyanoacetate (9.4 ml, 106.9 mmol), ammonium acetate (1.79 g, 26.17 mmol) and acetic acid (1.02 ml, 17.8 mmol) in benzene (75 ml) was heated at reflux in a 250 ml round bottom flask equipped with a Dean-Stark and a reflux condenser. After 3 h, TLC (25% EtOAc in hexane, PMA stain) showed the reaction was completed. After cooling, benzene (50 ml) was added and the layer was separated, the organic was washed by water (120 ml) and the aqueous layer was extracted by CH2Cl2 (3×120 ml). The combined organic was washed with sat'd NaHCO3, brine, dried and concentrated and the residual was purified by flash chromatography (340 g silica gel column, eluted by EtOAc in hexane: 5% EtOAc, 2 CV; 5-25%, 14 CV; 25-40%, 8 CV) gave a mixture of E and Z isomers: methyl 2-cyano-2-[6-oxaspiro[4.5]decan-9-ylidene]acetate (18.37 g, 87.8% yield, m/z 236.0 [M+H]+ observed) as a clear oil.

المصدر