Reacción #44022

Ecuación de reacción

Ethyl 1-(4-chlorophenylsulfonyl)-6-ethyl-4-oxopiperidine-2-carboxylate

ethyl 1-(4-chlorophenylsulfonyl)-6-ethyl-4-oxopiperidine-2-carboxylate

TMSCl

ethylene glycol

→

mixture

Rendimiento 96.0%

ethyl 8-(4-chlorophenylsulfonyl)-9-ethyl-1,4-dioxa-8-azaspiro[4.5]decane-7-carboxylate

Rendimiento 96.0%

Disolventes

CH2Cl2

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturarefluxed under nitrogen for 3 hours
2. 2
   ConcentraciónThe reaction mixture was concentrated tinder reduced pressure
3. 3
   LavadoThe aqueous layer was washed with several more portions of EtOAc
4. 4
   Secadodried over Na2SO4
5. 5
   Concentraciónconcentrated

Procedimiento

Ethyl 1-(4-chlorophenylsulfonyl)-6-ethyl-4-oxopiperidine-2-carboxylate (109; 5.31 g, 14.2 mmol), TMSCl (5.41 ml, 42.6 mmol), and ethylene glycol (3.96 ml, 71.0 mmol) were added to CH2Cl2 (50 ml) and refluxed under nitrogen for 3 hours. The reaction mixture was concentrated tinder reduced pressure, and taken up in equal portions of EtOAc and water. The aqueous layer was washed with several more portions of EtOAc, dried over Na2SO4, and concentrated to give 5.67 g (96%) of a mixture of cis/trans (4:96) isomers as a clear oil which solidified upon standing. The material was used without further purification.

Fuente