Umekubo N,
Yokoshima S.
*
Nagoya University, Japan
Total Syntheses of Malettinins C and E.
Org. Lett. 2023;
25: 4530-4533
DOI:
10.1021/acs.orglett.3c01565
Key words
(+)-malettinin C - (+)-malettinin E - asymmetric organocatalytic aldol reaction - Buchner ring expansion - Dess–Martin oxidation - oxidative dearomatization
Significance
Yokoshima and Umekubo report the synthesis of two tropolone-containing natural products, namely (+)-malettinin C and (+)-malettinin E. These compounds possess high binding affinities to metal ions and therefore serve as inhibitors to a range of metalloenzymes.
Comment
Synthetic endeavors started with an organocatalytic asymmetric aldol reaction. PIFA-mediated oxidative dearomatization of phenol K led to spirocycle M, which was converted to tropolone O in a base-mediated ring expansion, paving the way to malettinins C and E. Moreover, the authors showcased an improved cyclization sequence by replacing the nitro group in J by a sulfonyl group.
