Reacción #5805

Ecuación de reacción

diethyl ether

t-butyl alcohol

(±)-cis-4-(cyanomethyl)-1,5-dioxaspiro[5.5]-undecane-2-acetic acid

dicyclohexylcarbodiimide

→

(±)-cis-1,1-dimethylethyl 4-(cyanomethyl)-1,5-dioxaspiro[5.5]undecane-2-acetate

Disolventes

dichloromethane

dichloromethane

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato slowly warm to room temperature over a 16.5-hour period
2. 2
   workup.STIRRINGThe mixture is stirred one hour
3. 3
   workup.STIRRINGstirring continued four hours
4. 4
   Filtraciónfiltered
5. 5
   ConcentraciónThe filtrate is concentrated at reduced pressure
6. 6
   ConcentraciónThis crude concentrate
7. 7
   Otrois chromatographed on silica gel
8. 8
   Lavadoeluted with 4:1 hexane

Procedimiento

(±)-cis-4-(cyanomethyl)-1,5-dioxaspiro[5.5]-undecane-2-acetic acid 3.32 g (13.12 mmol), is dissolved in 15 mL of dichloromethane, cooled to 0° C. and 0.1 g of 4-dimethylaminopyridine (DMAP) added, followed y t-butyl alcohol, and followed by 3.25 g of dicyclohexylcarbodiimide (DCC). This solution is stirred and allowed to slowly warm to room temperature over a 16.5-hour period. TLC shows mainly product, and some slightly lower Rf by-product. The mixture is stirred one hour and 50 mL of dichloromethane is added and stirring continued four hours. One hundred mL of diethyl ether is added and then filtered. The filtrate is concentrated at reduced pressure. This crude concentrate is chromatographed on silica gel and eluted with 4:1 hexane:ethyl acetate to yield (±)-cis-1,1-dimethylethyl 4-(cyanomethyl)-1,5-dioxaspiro[5.5]undecane-2-acetate.

Fuente