2,4-Dimethoxybenzyl alcohol → rac-(trans)-Cyclopentane-1,2-dicarboxylic acid mono-(2,4-dimethoxy-benzyl)ester

Beteiligte Stoffe

Reaktionsschritte

To a solution of (trans)-cyclopentane-1,2-dicarboxylic acid (1.90 g, 12 mmol), 2,4-dimethoxy-benzyl alcohol (2.02 g, 12 mmol), DMAP (73 mg, 0.6 mmol) in DMF (30 mL), chilled in an ice bath, was added EDC.HCl (2.53 g, 13.2 mmol) in two portions. The mixture was stirred at ice bath temperature for 15 min and warmed to RT for 4 hrs. The reaction mixture was diluted with H2O (100 mL) and saturated NaHCO3 (40 mL). The aqueous mixture was extracted with EtOAC (3×30 mL), acidified to pH 3 with saturated KHSO4 and extracted with EtOAc (3×30 mL). The combined organic layers were washed with H2O (2×25 mL), saturated NaCl (25 mL), dried over MgSO4, filtered and evaporated. The crude material was re-dissolved in CHCl3 and eluted through a silica gel plug with CHCl3 (100 mL) and then EtOAc (100 mL). The EtOAc fraction was evaporated and pumped to a clear oil, 2.6 g (70%), and used without further purification.

Herkunft & Nachweise