PROCESS FOR PRODUCING $g(a),$g(a)-DIFLUORO- $g(b) -KETOESTER

WIPO Patent Application WO/2001/066509

A1

An acid halide represented by general formula [1] is reacted with a difluoroketene silyl acetal represented by general formula [2] preferably in the presence of a transition metal catalyst to obtain an $g(a), $g(a) -difluoro- $g(b) -ketoester represented by general formula [3]. According to need, the $g(b) - ketoester is subjected to an asymmetric hydrogenation reaction with the aid of a hydrogenation catalyst to induce the corresponding optically active $g(a), $g(a) - difluoro- $g(b) -hydroxyester. (In general formulae, R?1¿, R?2¿, R?3¿, R?4¿, and R?5¿ each represents, e.g., alkyl; and X?1¿ represents halogeno.) The process enables the $g(a), $g(a) - difluoro- $g(b) -ketoester to be mass-produced in high yield. Also provided are: a process for producing the difluoroketene silyl acetal usable as an intermediate in that process; and a process for efficiently mass-producing an optically active $g(a),$g(a)difluoro-$g(b)-hydroxyester from the $g(b)-ketoester.

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ISEKI KATSUHIKO (JP)
KUROKI YOSHICHIKA (JP)
SAKAMAKI YUKO (JP)

PCT/JP2001/001103

September 13, 2001

February 15, 2001

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DAIKIN IND LTD (JP)
ISEKI KATSUHIKO (JP)
KUROKI YOSHICHIKA (JP)
SAKAMAKI YUKO (JP)

B01J27/122; B01J31/24; C07B53/00; C07B61/00; C07C67/00; C07C67/317; C07C67/347; C07C67/46; C07C69/675; C07C69/716; C07F7/18; (IPC1-7): C07C67/00; C07C67/317; C07C69/675; C07C69/716; C07F7/18

JPH0267250A	1990-03-07
EP0120368A2	1984-10-03
JPH11302226A	1999-11-02

Osaka, Hiromu (Shibazaki-cho 2-chome Tachikawa-shi Tokyo, JP)

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