Reaction of diketene with Grignard reagents in the presence of cobalt catalyst. A convenient method for the synthesis of 3-methylenealkanoic acids leading to …

T Fujisawa, T Sato, Y Gotoh, M Kawashima…

Index: Fujisawa, Tamotsu; Sato, Toshio; Gotoh, Yoshihiko; Kawashima, Masatoshi; Kawara, Tatsuo Bulletin of the Chemical Society of Japan, 1982 , vol. 55, # 11 p. 3555 - 3559

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Citation Number: 28

Abstract

Primary alkyl Grignard reagents react regioselectively with diketene in the presence of cobalt (II) iodide to afford 3-methylenealkanoic acids in good yields. The synthetic utility of this reaction is demonstrated in the syntheses of terpenoids by two methods. Utilizing the isomerization of double bond of 3-methylenealkanoic acids, geranic acid and farnesic acid were obtained in two steps. Another method, the tandem [3, 3] sigmatropic rearrangement ...