Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast.
Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)(3), iron(III) triflate, Fe(OTf)(3), copper(II) triflate, Cu(OTf)(2), and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.
Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama 700-8530, Japan. kuninobu@cc.okayama-u.ac.jp
Yoichiro
Y
Kuninobu
Atsushi
A
Kawata
Taihei
T
Noborio
Syun-Ichi
S
Yamamoto
Takashi
T
Matsuki
Kazumi
K
Takata
Kazuhiko
K
Takai