Reaktion #87968

Reaktionsgleichung

(±)-2,5-dioxopyrrolidin-1-yl 2-methyl-5-phenyl pentanoate

(±)-2,5-dioxopyrrolidin-1-yl 2-methyl-5-phenylpentanoate

R-(−)-2-phenylglycinol

→

title compound

Ausbeute 34.0%

(S)—N—((R)-2-hydroxy-1-phenylethyl)-2-methyl-5-phenylpentanamide

Ausbeute 34.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   SonstigeA white precipitate formed
3. 3
   Filtrationwhich was filtered from the reaction mixture
4. 4
   Waschenwashed with THF
5. 5
   EinengenThe filtrate was concentrated under vacuum
6. 6
   Sonstigewas chromatographed on silica gel
7. 7
   WaschenElution with ethyl acetate-heptane (50:50 v/v)

Vorschrift

To a solution consisting of (±)-2,5-dioxopyrrolidin-1-yl 2-methyl-5-phenyl pentanoate (18mb(i), 85.6 g, 296 mmol) in THF (3000 mL) at 48° C. was added R-(−)-2-phenylglycinol (65.9 g, 480 mmol, Bridge Organics) in portions. The resulting reaction mixture was stirred at 48° C. for 40 hours. A white precipitate formed, which was filtered from the reaction mixture and washed with THF. The filtrate was concentrated under vacuum and the residue, comprising the diastereomeric pair, was chromatographed on silica gel. Elution with ethyl acetate-heptane (50:50 v/v) afforded the pure diastereomer title compound (31.3 g, 34%) as a colorless solid; TLC Rf 0.205 (solvent system: 50:50 v/v ethyl acetate-heptane); HPLC retention time 15.1 minutes, stationary phase: Gemini 5μ C18 250×4.6 mm, ultraviolet detector at 210 nm, mobile phase: 1 mL/min, 60:40:0.1 v/v methanol-water-acetic acid.

Quelle