Practical asymmetric synthesis of (S)-MA20565, a wide-spectrum agricultural fungicide.
A practical asymmetric synthesis of a wide-spectrum agricultural fungicide, (S)-MA20565 (1), is described. The convergent synthesis was achieved starting from commercially available 3-(trifluoromethyl)aniline (7) in 44% overall yield through five steps and 2-bromobenzaldehyde (9) in 48% overall yield through four steps, respectively. (S)-O-[1-(3-Trifluoromethylphenyl)ethyl]hydroxylamine (2), a key intermediate of 1, was prepared via ruthenium(II)-catalyzed asymmetric transfer hydrogenation of 1-(3-trifluoromethylphenyl)ethanone (6) followed by chlorination using methanesulfonyl chloride and oxyamination using potassium acetohydroxamate with high level of stereocontrol.
Tanaka
K
K
Tsukuba Research Center, Mitsubishi Chemical Corporation, 8-3-1 Chuo, Ami, Inashiki, Ibaragi 300-0332, Japan.
Katsurada
M
M
Ohno
F
F
Shiga
Y
Y
Oda
M
M
Miyagi
M
M
Takehara
J
J
Okano
K
K
D000081:Acetamides / Q000138:chemical synthesis* / Q000737:chemistry; D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D005659:Fungicides, Industrial / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared
D000081:Acetamides; D000577:Amides; D000588:Amines; D005659:Fungicides, Industrial; D007097:Imines; C414084:MA 20565