Double Reformatsky Reaction: Divergent Synthesis of δ-Hydroxy-β-ketoesters
Masahiro Mineno*, Yasuhiro Sawai, Kazuaki Kanno, Naotaka Sawada and Hideya Mizufune
*Chemical Development Laboratories, CMC Center, Takeda Pharmaceutical Company Limited, 2-17-85, Juso-honmachi, Yodogawa-ku, Osaka 532-8686, Japan, Email: masahiro.minenotakeda.com
M. Mineno, Y. Sawai, H. Kanno, N. Sawada, H. Mizufune J. Org. Chem., 2013, 78, 5843-5850.
DOI: 10.1021/jo400408t (free Supporting Information)
A tandem addition of two molecules of zinc alkanoate to a carbonyl compound gives a series of δ-hydroxy-β-ketoesters. The key to accelerate such a double Reformatsky reaction is considered to be a complex-induced proximity effect of the in situ generated zinc alkoxide coordinated with a bidentate amine. A feature of the reaction system is its high tolerance of functional groups due to the moderate nucleophilicity of organozinc reagents.
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