Page 226 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant

214 hydrolysis, oxidation and reduction

. Saturated aqueous sodium bicarbonate solution, 30 mL
. Brine, 30 mL
. Magnesium sulfate, 3 g
. Ethyl acetate, hexane
. Silica gel 60
. Column chromatography
. Test tubes, 25 mL 50

. 100 mL Three-necked and 50 mL two-necked round-bottom flask with mag-
netic stirrer bars
. Magnetic stirrer
. Dry ice±acetone cooling bath
. Thermometer, ÿ80 8C to 30 8C
. Syringes
. TLC
. Separatory funnel
. Cannula
. Rotary evaporator

Procedure [4]

1. To (Z)-2-acetamino-cinnamic acid (1.03 g, 5.0 mmol) in dry THF (20 mL) was
0
added 1,1 -carbonyldiimidazole (1.28 g, 5.5 mmol) at room temperature; then
lithiated ethyl acetate (15 mmol) was added via cannula at ÿ78 8C.
2. The reaction mixture was stirred at the same temperature for 30 min, then
stirred at 0 8C for 30 min, and poured into NH 4 Cl aq. solution.
3. The aqueous layer was extracted with ethyl acetate and combined organic
layer was washed with NaHCO 3 and brine, then dried over MgSO 4 .
4. After removal of the solvent, the residue was chromatographed over silica
gel to afford ethyl (Z)-4-acetamido-3-oxo-5-phenyl-4-pentenoate (870 mg,
63 %).

13.1.2 ASYMMETRIC HYDROGENATION OF ETHYL 4-
ACETAMIDO-3-OXO-5-PHENYL-4-PENTENOATE

-
Ph Rh[(cod)(S)-BiNAP]+ClO 4 Ph
and RuBr 2 [(S)-BiNAP]
OEt OEt
AcHN AcHN
1) H 2 (10 atm), 24 h
O O 2) H 2 (90 atm), 24 h OH O
1 2
-
Rh[(cod)(S,S)-diop]+ClO 4 Ph
and RuBr 2 [(S)-BiNAP]
1 AcHN OEt
1) H 2 (10 atm), 24 h
2) H 2 (90 atm), 24 h OH O
3