Synthesis 2015; 47(19): 2957-2960
DOI: 10.1055/s-0034-1381045
special topic
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Tribenzotropone by Ring Expansion of Phenanthrene-9,10-dione

Jeongae Choi
a   Department of Energy and Biotechnology, Myong Ji University, Myongji-Ro 116, Cheoin-Gu, Yongin, Gyeonggi-Do, 449-728, Republic of Korea
,
Hyunuk Jung
a   Department of Energy and Biotechnology, Myong Ji University, Myongji-Ro 116, Cheoin-Gu, Yongin, Gyeonggi-Do, 449-728, Republic of Korea
,
Jeong-Eun Yeo
b   Department of Chemistry, Myong Ji University, Myongji-Ro 116, Cheoin-Gu, Yongin, Gyeonggi-Do, 449-728, Republic of Korea   Email: sangkoo@mju.ac.kr
,
Sangho Koo*
a   Department of Energy and Biotechnology, Myong Ji University, Myongji-Ro 116, Cheoin-Gu, Yongin, Gyeonggi-Do, 449-728, Republic of Korea
b   Department of Chemistry, Myong Ji University, Myongji-Ro 116, Cheoin-Gu, Yongin, Gyeonggi-Do, 449-728, Republic of Korea   Email: sangkoo@mju.ac.kr
› Author Affiliations
Further Information

Publication History

Received: 15 April 2015

Accepted after revision: 05 June 2015

Publication Date:
07 August 2015 (online)


Abstract

Tribenzotropone was efficiently synthesized by a ring-expansion method from readily available phenanthrene-9,10-dione via a ring-opened diketone as a key intermediate; the diketone was prepared by nucleophilic addition of allyl and vinyl groups, followed by an oxidative ring-opening reaction with lead(IV) acetate. Ring closure by an intramolecular Diels–Alder reaction and subsequent dehydrogenation produced tribenzotropone in 38% overall yield. Ring closure by a Morita–Baylis–Hillman reaction, on the other hand, produced a dibenzo-fused nonanedione in 22% overall yield.

Supporting Information