Umekubo N,
Suga Y,
Hayashi Y.
* Tohoku University, Sendai, Japan
Pot and Time Economies in the Total Synthesis of Corey Lactone.
Chem. Sci. 2020;
11: 1205-1209
Key words
Corey lactone - amine catalysis - Michael addition - cascade reaction - asymmetric
synthesis
Significance
Hayashi and co-workers report an organocatalytic domino Michael/Michael reaction of
α,β-unsaturated aldehydes and ethyl (E)-4-oxopent-2-enoate that uses a diphenylprolinol silyl ether as catalyst. The desired
cyclopentanones were obtained in good to excellent yields and with excellent diastereo-
and enantioselectivities. The newly developed formal (3+2) cycloaddition was applied
as the key step in a concise and highly stereoselective route towards the Corey lactone.
Comment
Due to its importance as a crucial intermediate for the synthesis of various prostaglandin
hormones, efficient, selective, and practical routes toward the Corey lactone are
desirable. The authors have developed a time-efficient organocatalytic protocol consisting
of seven steps in a single reaction vessel that furnishes enantiopure Corey lactone.
The required silyl acrylaldehyde is accessible through an atom-economic trimerization
of ethyne, carbon monoxide, and dimethyl(phenyl)silane (I. Matsuda, A. Ogiso, S.
Sato, Y. Izumi J. Am. Chem. Soc. 1989, 111, 2332).
