Pyridine → Ethyl (-)-lactate triflate
Reaction equation
[F:1][C:2]([F:15])([F:14])[S:3]([O:6]S(C(F)(F)F)(=O)=O)(=[O:5])=[O:4].[CH2:16]([O:18][C:19](=[O:23])[CH:20](O)[CH3:21])[CH3:17].N1C=CC=CC=1>ClCCl>[F:1][C:2]([F:15])([F:14])[S:3]([O:6][CH:20]([CH3:21])[C:19]([O:18][CH2:16][CH3:17])=[O:23])(=[O:5])=[O:4]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a stirred solution of trifluoromethanesulfonic anhydride (30 mL, 170 mmol) in anhydrous dichloromethane (50 mL) was added drop-wise a solution of 2-hydroxypropanoic acid ethyl ester (20 g, 170 mmol) and pyridine (14 mL) in dichloromethane (50 mL) at 0° C. (Ice bath) over a period of 1 h under nitrogen. The ice bath was then removed and the reaction mixture was stirred for additional 2 h. The inorganic salt was then filtered off and the organic solution was washed with water, dried over sodium sulfate, and evaporated to give desired product as pink colored oil (37.4 g, 88%) which was used as such for the next step. 1HNMR (300 MHz, CDCl3): δ 1.38 (t, J=4.8 Hz, 3H), 1.77 (d, J=4.8 Hz, 3H), 4.32-4.37 (m, 2H) and 5.28 (q, J=6.9 Hz, 1H).