Synthesis 2020; 52(24): 3811-3817
DOI: 10.1055/s-0040-1706471
psp

Gram-Scale Robust Synthesis of 1-Chloro-2,3-dimethyl-4-phenylnaphthalene: A Promising Scaffold with Three Contiguous Reaction Positions

Kento Moriguchi
,
Taro Kono
,
Shinzo Seko
,
Yoo Tanabe
Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo, 669-1337, Japan   Email: tanabe@kwansei.ac.jp
› Author Affiliations
This research was partially supported by Grant-in-Aids for Scientific Research on Basic Areas (B) ‘18350056’, Priority Areas (A) ‘17035087’ and ‘18037068’, (C) 15K05508, and Exploratory Research ‘17655045’ from the Ministry of Education, Culture, Sports, Science and Technology (MEXT).


Abstract

A three-step reaction sequence for the gram-scale synthesis of 1-chloro-2,3-dimethyl-4-phenylnaphthalene was developed. (i) Stereoselective dichlorocarbene addition to methyl angelate afforded methyl (1S*,3S*)-2,2-dichloro-1,3-dimethylcyclopropane-1-carboxylate (78% yield, >98% purity, distillation). (ii) Addition reaction of two molar amounts of PhLi afforded (1S*,3S*)-2,2-dichloro-1,3-dimethylcyclopropyldiphenylmethanol (81% yield, >98% purity, recrystallization). (iii) Key SnCl4-mediated benzannulation produced the desired product (83% yield, >98% purity, recrystallization) with three contiguous reaction sites. Five derivatization examples including benzylic reactions and cross-couplings at the pendant Cl-position are demonstrated. Some relevant distinctive benzannulations are also discussed.

Supporting Information



Publication History

Received: 22 July 2020

Accepted after revision: 14 August 2020

Article published online:
30 September 2020

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