Page 120 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant

106 hydrolysis, oxidation and reduction

. AD-mix-b, 20 g
. Methanesulfonamide, 1.36 g
. Osmium tetroxide (4 wt% solution in water), 0.36 mL
. (1-Cyclohexenyl)acetonitrile, 1.73 g
. Sodium metabisulfite (Na 2 S 2 O 5 ), 14 g
. Dichloromethane, 360 mL
. Magnesium sulfate
. Ether, petroleum ether
. (40±63 mm) Silica gel 60, 30 g

. 250 mL Round-bottomed flask with a magnetic stirrer bar
. Magnetic stirrer
. Separating funnel, 500 mL
. Sintered glass funnel (4 cm)
. Flash column chromatography (30 cm 2:5 cm)

Procedure

1. In a 250 mL round-bottomed flask equipped with a magnetic stirrer bar were
placed a 1:1 mixture of tert-butanol and water (140 mL), AD-mix-b (20 g)
[5]
and methanesulfonamide (1.36 g) .
100 g of AD-mix-b are made up of potassium osmate (0.052 g),
(DHQD) PHAL (0.55 g), K 3 Fe(CN) (70 g), K 2 CO 3 (29.4 g).
6
2
2. The mixture was stirred for a few minutes at room temperature until two
clear phases were produced. To the ice-chilled reaction mixture were succes-
sively added osmium tetroxide (4 wt% in water, 0.36 mL) and (1-cyclohex-
enyl)-acetonitrile (1.73 g). The reaction mixture was stirred vigorously for 8
hours at 0 8C.
3. The reaction was monitored by TLC (eluent: petroleum ether±ether, 4:1).
Olefin and diol spots, visualized by iodine vapour, have R f values of 0.43
and zero respectively.
4. Sodium metabisulfite (14 g) was added to the reaction mixture and stirring
was continued for 1 hour.
5. The reaction mixture was transferred to a separating funnel and extracted
three times with dichloromethane (3 120 mL). The combined organic
phases were dried over magnesium sulfate, filtered and concentrated using
a rotary evaporator. The residue was purified by flash chromatography on
silica gel (eluent: ether±petroleum ether, 3:2) to give a crystalline product
[6]
(2.1 g, 94 %), mp 95±101 8C, [a] 20 ÿ 1:6 (c 1, CHCl 3 ) .
D
The ee (66±71 %) was determined on the acetonide derivative by GC
analysis.
1
H NMR (200 MHz, CDCl 3 : d 1.3±1.8 (m, 7 H), 2.0 (m, 1 H), 2.58 (d ‡
brs, 2 H, J 17 Hz, CH CN, OH), 2.73 (d ‡ brs, 2 H, J 17 Hz, CH CN, OH),
b
a
3.52 (dd, 1 H, J 4.4 and 10.3 Hz, CHOH).
13
C NMR (50.3 MHz, CDCl 3 ): d 20.6, 23.7, 28.8, 30.4, 34.6, 72.1, 117.9.