Ethylene Glycol → 5-(2-Methyl-[1,3]dioxolan-2-yl)-pentanoic acid

Participants

Reaction Steps

A mixture of ketone 2-1 (18 g, 105 mmol), ethylene glycol (3.2 ml, 110 mmol), p-TSA (50 mg, 0.2713 mmol) and toluene (300 mL) was heated to reflux with azeotropic removal of water for 24 hours. The reaction mixture was diluted with EtOAc and then washed with sat. NaHCO3, brine, dried (MgSO4), and concentrated. The residue was dissolved in EtOH (200 ml) and then treated with 1N NaOH (120 ml, 120 mmol). After 2 h, the reaction was poured into 600 mL 2:1 Et2O/10% KHSO4. The organic portion was separated, washed with brine, dried (MgSO4) and concentrated to give acid 2-2 as a colorless oil.

Provenance & Evidence