Reaction #7773

Reaction equation

EtOAc

1,4-Cyclohexanedione mono-ethylene ketal

Lithium bis(trimethylsily)amide

ethyl cyanoformate

→

8-oxo-1,4-dioxa-spiro[4.5]decane-7-carboxylic acid ethyl ester

Solvents

water

THF

THF

Conditions

Workup

1. 1
   workup.WAITAfter 60 min
2. 2
   workup.ADDITIONcontaining ice
3. 3
   WashThe organic layer was washed with water and brine before it
4. 4
   Otherwas dried
5. 5
   Concentrationconcentrated
6. 6
   FiltrationThis crude was filtered through a plug of silica

Procedure

1,4-Cyclohexanedione mono-ethylene ketal (25 g) was dissolved in THF and cooled to −78° C. 1.0 M Lithium bis(trimethylsily)amide (160 mL) in THF was added dropwise. After 30 min, ethyl cyanoformate (15.9 mL) was added dropwise. After 60 min, the solution was poured into EtOAc and water containing ice. The organic layer was washed with water and brine before it was dried and concentrated. This crude was filtered through a plug of silica to give the 8-oxo-1,4-dioxa-spiro[4.5]decane-7-carboxylic acid ethyl ester (32.4 g). MS found: (M+H)+=228.9.

Source