Page 139 - Catalysts for Fine Chemical Synthesis Vol 1 - Robert & Poignant

126 hydrolysis, oxidation and reduction

. n-Hexane (degassed) 2.5 ml
. Acetone (degassed) 11 ml
. 1.45 M HBr/Methanol

. Schlenk tube
. Magnetic stirrer
. Magnetic stirrer bar
. Oil bath
. Cannula
. Rotary evaporator

Procedure
1. In a Schlenk tube, equipped with a magnetic stirrer bar, were placed BisP*
(77 mg), bis(2-methylallyl)cyclooctadieneruthenium (II) (105 mg), and de-
gassed n-hexane (2.5 mL) under an argon atmosphere. The mixture was
stirred at 60 8C for 10 hours.
2. To the reaction mixture, degassed n-hexane 5 mL was added. The solution was
passed through a cannula capped with a filter paper, and concentrated in
vacuo.
3. The resulting solid was dissolved in degassed acetone (11 mL). To this
solution, 1.45 M methanolic hydrogen bromide (0.384 mL) was added drop-
wise. The mixture was stirred for two hours.
4. The mixture was filtered by passing through a cannula capped with a filter
paper, and the solvent was removed in vacuo to afford 1,2-bis(tert-buty-
lmethylphosphino)ethaneruthenium(II) bromide.

9.4.3 SYNTHESIS OF (R)-(ÿ)-METHYL
3-HYDROXYPENTANOATE [40] USING (BisP*ÿRu)

O O RuBr 2 (BisP*), H 2 OH O
O MeOH O

Materials and equipment
. Methanol±distilled water (10:1), 200 mL
. BisP*±RuBr 2 52 mg,
. Methyl 3-oxopentanoate 10.7 g
. Argon, hydrogen
. Silica gel
. Chloroform, acetone

. Low pressure hydrogenator equipped with a 500 mL glass autoclave, a heater,
and a magnetic stirrer