Synthesis 2022; 54(23): 5324-5336
DOI: 10.1055/a-1916-4510
paper

Asymmetric Synthesis of ent-Anorisol A and Its Stereoisomers and Confirmation of the Absolute Configuration of Anorisol A Isolated from Anogeissus rivularis

Rungrawin Chatpreecha
,
,
Pawaret Leowanawat
,
,
This project is funded by the National Research Council of Thailand (NRCT) and Mahidol University (N42A650346), the Center of Excellence for Innovation in Chemistry (PERCH-CIC), the Ministry of Higher Education, Science, Research and Innovation, Thailand, and the Office of the Higher Education Commission and Mahidol University under the National Research Universities Initiative. A student scholarship to R.C. from the Science Achievement Scholarship of Thailand (SAST) is gratefully acknowledged.


Abstract

Asymmetric synthesis of (2S,3S,4R,5S)-2-(2,4-dihydroxyphenyl)-5-(4-methoxyphenyl)-3,4-dimethyltetrahydrofuran, named as ent-anorisol A, was accomplished. The uncommon relative 2,3-anti-3,4-syn-4,5-syn stereochemistry across the tetrahydrofuran ring of ent-anorisol A was constructed with high yield and good stereoselectivity via an acid-catalyzed direct cyclization of unprotected chiral 1,4-diarylbutane-1,4-diol with non-symmetrical aromatic rings. Except for the sign of the specific rotation value, the spectroscopic data of the synthetic ent-anorisol A are in good agreement with those reported for natural anorisol A isolated from Anogeissus rivularis. In addition, the (2R,3S,4R,5R) and (2S,3S,4R,5R) isomers of anorisol A were also synthesized. Comparison of the specific rotation value and the experimental electronic circular dichroism data of natural anorisol A with those of the synthesized ent-anorisol A, (2R,3S,4R,5R), and (2S,3S,4R,5R) derivatives confirms the 2R,3R,4S,5R configurations assigned for natural anorisol A.

Supporting Information



Publikationsverlauf

Eingereicht: 02. Juni 2022

Angenommen nach Revision: 02. August 2022

Accepted Manuscript online:
02. August 2022

Artikel online veröffentlicht:
01. September 2022

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