Page 92 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant
P. 92
78 hydrolysis, oxidation and reduction
(2R,3R)-enantiomer: R t 13.5 min. The analysis of the ester derived from ()-
MTPA chloride did not give any resolution by 19 F NMR.
1 H NMR (200 MHz, CDCl 3 ): d 7.23±7.34 (m, 5H, Ph); 4.19 (s, 1H,
CH); 3.68±3.88 (m, 2H, CH 2 ); 1.84±1.77 (m, 1H, OH); 1.06 (s, 3H,
CH 3 ).
ÿ1
IR (CHCl 3 , cm ): 3589, 3450, (O±H), 3060 (C±H epoxide), 3010 (C±H
aromatic), 2938, 2878 (C±H aliphatic), 1713, 1603, 1493, 1452 (CC), 1385,
1204 (C±OH, C±O±C), 1095, 1058, 1029, 980, 924, 898, 850.
5.2.3 EPOXIDATION OF (E)-2-HEXEN-1-OL [4]
Ti(O-iPr) 4, (+)-DET O
OH OH
t-BuOOH, CH 2 Cl 2
(2S, 3S )
Materials and equipment
. l-()-Diethyl tartrate ( ()-DET), 250 mg, 1.2 mmol, 0.06 eq
Ê
. Dichloromethane stored over preactivated 3 A molecular sieves, 40 mL
Ê
. Activated powdered 4 A molecular sieves, 600 mg
. Titanium isopropoxide, 297 mL, 1 mmol, 0.05 eq
. Anhydrous solution of 5.5 M of tert-butyl hydroperoxide in isooctane stored
over molecular sieves, 7.2 mL, 40 mmol, 2 eq
. (E)-2-Hexen-1-ol, 2 g, 20 mmol
. Solution of ferrous sulfate heptahydrate, 6.6 g, 24 mmol, and tartaric acid,
2 g, 12 mmol, in deionized water, 20 mL
. Sodium hydroxide solution in saturated brine, 30 %, 50 mL
. Sodium sulfate
. Silica gel 60 (0.063±0.04 mm)
. (R)-()-a-Methoxy-a-(trifluoromethyl)phenylacetyl chloride (MTPA chlor-
ide) or the (S)-enantiomer, 5 mg, 0.02 mmol
. 4-Dimethylaminopyridine (DMAP), 5 mg, 0.04 mmol
. n-Hexane, ethyl acetate, diethyl ether, triethylamine
. p-Anisaldehyde
. 50 mL Two-necked flask with a magnetic stirrer bar
. Magnetic stirrer
. Acetone/Dri-ice cooling bath equipped with contact thermometer, ÿ20 8C
. Syringes
. Beaker, 100 mL
. Separating funnel, 250 mL
. Rotary evaporator
