Reaktion #83737

ord-375ecb3630cc46b09b755aefa78342ef

Reaktionsgleichung

CCOC(=O)C1=C(NC(C)=O)C(=O)O[C@H]1C
(S)-2-acetamido-3-ethoxycarbonyl-2-penten-4-olide
→
CCOC(=O)[C@@H]1[C@H](C)OC(=O)[C@@H]1NC(C)=O
title compound
CCOC(=O)[C@@H]1[C@H](C)OC(=O)[C@@H]1NC(C)=O
2(R)-acetamido-3(S)-ethoxycarbonyl-4(S)-pentanolide

Edukte

CCOC(=O)C1=C(NC(C)=O)C(=O)O[C@H]1C
(S)-2-acetamido-3-ethoxycarbonyl-2-penten-4-olide
—
( 2R,3R,4S )
—
crude product
—
( 2S,3R,4S )

Reagenzien

—
rhodium Al2O3

Lösungsmittel

ClC(Cl)Cl
CHCl3
CCOC(C)=O
ethyl acetate
CCOC(C)=O
ethyl acetate

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Sonstigeis hydrogenated at 50° C.

Vorschrift

0.45 g of rhodium/Al2O3 catalyst is added to 15 g of (S)-2-acetamido-3-ethoxycarbonyl-2-penten-4-olide dissolved in 100 ml of ethyl acetate and the whole is hydrogenated at 50° C. and 50 bars for 21 hours and worked up as in Example 14. The ratio of the diastereoisomers of the crude product exhibited by HPLC analysis is (2R,3S,4S):(2S,3R,4S):(2R,3R,4S)=approximately 85:13:2. Diastereoisomerically pure title compound is obtained by crystallisation from ethyl acetate, [α]D20 =-183.2° (3% in CHCl3), m.p. 165°-167° C.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US05625059uspto-grants-1997_04