Synlett 2021; 32(11): 1085-1088
DOI: 10.1055/a-1480-5225
letter

A Concise Synthesis of 24,25-Dihydro-6-epi-Monanchosterol A

,
Vladimir Kjartan Stojadinovic
,
Jörg-Martin Neudörfl
,

This work was supported by the University of Cologne.


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Abstract

We report the first synthetic entry to a steroid with an unusual bicyclo[4.3.1]dec-3-en-10-one A/B ring substructure as a close structural analogue of the anti-inflammatory monanchosterols. Under optimized conditions, regioselective cis-dihydroxylation of the Δ5-double bond of 7-dehydrocholesterol and subsequent Criegee oxidation yields the corresponding 5,6-seco-steroid as a pure Z-isomer which upon treatment with K2CO3 in MeOH diastereoselectively affords 24,25-dihydro-6-epi-monanchosterol A through intramolecular aldol addition (cyclization). The developed three-step sequence proceeds in 17% overall yield without the need of any protecting group. The title compound was characterized by X-ray crystallography.

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Publikationsverlauf

Eingereicht: 25. Februar 2021

Angenommen nach Revision: 12. April 2021

Accepted Manuscript online:
12. April 2021

Artikel online veröffentlicht:
29. April 2021

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