Synlett 2023; 34(17): 2011-2016
DOI: 10.1055/a-2124-4161
letter

Study on Integrated Synthesis of Dimeric Pyranonaphthoquinones: Preparation of Versatile Synthetic Intermediate and Conversion into ent-Hemi-actinorhodin and ent-Hemi-γ-actinorhodin

Yoshio Ando
,
Mark M. Maturi
,
Taiju Hoshino
,
Nozomi Tanaka
,
Takahiro Sakai
,
,
This research was supported by the Japan Society for the Promotion of Science (JSPS KAKENHI, Grant No. JP16H06351, JP21H04703), the Takeda Science Foundation, and the TOBE MAKI Scholarship Foundation.


In memory of Professor Yoshito Kishi

Abstract

For developing general synthetic access toward dimeric pyranonaphthoquinones including β-naphthocyclinone, actinorhodin, and γ-actinorhodin, we report stereodefined 6,9,10-trioxypyranonaphthalene as a versatile intermediate. Its robust preparation started from ethyl (S)-4-chloro-3-hydroxybutyrate. The pyranonaphthalene core was constructed by a Michael–Dieckmann sequence, and methylation using Me3Al and BF3·OEt2 established the required trans structure in a scalable manner. Conversion of this intermediate into ent-hemi-actinorhodin and into ent-hemi-γ-actinorhodin are also reported, in which the conditions for the oxidative lactonization were optimized.

Supporting Information



Publication History

Received: 22 June 2023

Accepted after revision: 06 July 2023

Accepted Manuscript online:
06 July 2023

Article published online:
28 August 2023

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