Total Synthesis of (±)-Niduterpenoid B

Erick M. Carreira; Tristano C. Martini

doi:10.1055/a-2439-7388

Synfacts, Table of Contents

Synfacts 2024; 20(12): 1233
DOI: 10.1055/a-2439-7388

Synthesis of Natural Products

Total Synthesis of (±)-Niduterpenoid B

Contributor(s):

Erick M. Carreira

,

Tristano C. Martini

Abstract

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Xue Y, Hou S-H *, Zhang X, Zhang F-M, Zhang X-M, Tu Y-Q *. Shanghai Jiao Tong University and Lanzhou University, P. R. of China
Total Synthesis of the Hexacyclic Sesterterpenoid Niduterpenoid B via Structural Reorganization Strategy.

J. Am. Chem. Soc. 2024;
146: 25445-25450
DOI: 10.1021/jacs.4c09555

Keywords

(±)-niduterpenoid B - Horner–Wadsworth–Emmons reaction - Knoevenagel condensation - Krapcho decarboxylation - Alcaraz reaction - Johnson–Claisen rearrangement - cyclopropanation

Significance

Niduterpenoid B is characterized by a 5 /5 /5 /5 /3 /5 hexacyclic framework featuring 13 contiguous stereocenters, four of which are quaternary. The total synthesis by Tu and co-workers capitalizes on a cascade reaction wherein the tetraquinane scaffold, with its stereocenters, is rapidly assembled. The full core of the molecule is later accessed via a rhodium-mediated cyclopropanation.

Comment

Cyclobutanone A, assembled by [2 + 2] cycloaddition of cyclopentadiene and methoxy(methyl)ketene, was converted into key triene E. Exposure of E to Lewis and Brønsted acid catalysis initiated the Nazarov cyclization/double ring expansion/elimination reaction which, after Krapcho decarboxylation, returned tetraquinane F. The highly strained three-membered ring in J was installed via cyclopropanation of diazo ketone I, which served as synthetic intermediate to complete the synthesis of niduterpenoid B.

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