Citric Acid → 8-Ethyl-1,4-dioxaspiro[4,4]nonane-7-carboxylic acid
Reaction equation
[CH2:1]([CH:3]1[CH2:11][C:6]2([O:10][CH2:9][CH2:8][O:7]2)[CH2:5][CH:4]1[C:12]([O:14]CC)=[O:13])[CH3:2].[OH-].[Na+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C(Cl)Cl>[CH2:1]([CH:3]1[CH2:11][C:6]2([O:7][CH2:8][CH2:9][O:10]2)[CH2:5][CH:4]1[C:12]([OH:14])=[O:13])[CH3:2]Participants
5
Procedure
A round bottom flask was charged with ethyl 8-ethyl-1,4-dioxaspiro[4.4]nonane-7-carboxylate (0.32 g, 1.4 mmol) and aqueous 1 N sodium hydroxide (14.0 mL, 14.0 mmol). The solution was stirred overnight at rt. To the solution was added DCM (30 mL) followed by the addition of 20% aqueous citric acid (about 20 mL) to reach pH of about 2. The layers were separated and the aqueous solution was extracted with DCM (2×30 mL) and DCM/EtOAc (1:1, 30 mL). The combined extracts were dried over anhydrous MgSO4, filtered, and concd under reduced pressure to give 8-ethyl-1,4-dioxaspiro[4.4]nonane-7-carboxylic acid as a clear, colorless oil (0.27 g, 96%): LC/MS (Table 1, Method c) Rt=1.20 min; MS m/z: 201 (M+H)+.
Workup
- customThe layers were separated
- extractionthe aqueous solution was extracted with DCM (2×30 mL) and DCM/EtOAc (1:1, 30 mL)
- dry with materialThe combined extracts were dried over anhydrous MgSO4
- filtrationfiltered
Sources & evidence
- ORD record
- ord-9fe32e1c33aa492ea2a9878d0f7eab39
- Source dataset
- uspto-grants-2013_04
- Patent number
- US08426411B2
Reaction notes
Loading…