Reaktion #819554

Reaktionsgleichung

2,2,2-trichloro-acetimidic acid 4-methoxybenzyl ester

(2R,4R)-4-hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

methanol

→

title compound

Ausbeute 84.2%

(2R,4R)-4-(4-Methoxy-benzyloxy)-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

Ausbeute 84.2%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrate
2. 2
   workup.DISSOLUTIONDissolve in 25:75 dichloromethane
3. 3
   Filtrationhexanes, filter away the insolubles
4. 4
   Sonstigepurify
5. 5
   Waschenfiltrate (silica gel chromatography, eluting with dichloromethane/ethyl acetate mixtures)

Vorschrift

Add lanthanum triflate (3.6 g, 6.16 mmol) to a solution of 2,2,2-trichloro-acetimidic acid 4-methoxybenzyl ester (52.2 g, 185 mmol) and (2R,4R)-4-hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (30.2 g, 123 mmol) in toluene (200 mL). Stir 2.5 h, add methanol and concentrate. Dissolve in 25:75 dichloromethane:hexanes, filter away the insolubles and purify filtrate (silica gel chromatography, eluting with dichloromethane/ethyl acetate mixtures) to give the title compound (37.85 g, 84%).

Quelle