Synthesis 2019; 51(03): 704-712
DOI: 10.1055/s-0037-1610996
paper
© Georg Thieme Verlag Stuttgart · New York

Cleavage of Catechol Monoalkyl Ethers by Aluminum Triiodide–Dimethyl Sulfoxide

Dayong Sang
,
Juan Tian*
Jingchu University of Technology, 33 Xiangshan Road, Jingmen, Hubei 448000, P. R. of China   Email: Tianjuan@jcut.edu.cn
,
Xiaodong Tu
,
Zhoujun He
,
Ming Yao
› Author Affiliations
This work was supported by Jingchu University of Technology (QDB201707) and Hubei Provincial Department of Education (B2018234).
Further Information

Publication History

Received: 25 July 2018

Accepted after revision: 31 August 2018

Publication Date:
26 September 2018 (online)


Abstract

Using eugenol and vanillin as model substrates, a practical method is developed for the cleavage o-hydroxyphenyl alkyl ethers. Aluminum oxide iodide (O=AlI), generated in situ from aluminum triiodide and dimethyl sulfoxide, is the reactive ether cleaving species. The method is applicable to catechol monoalkyl ethers as well as normal phenyl alkyl ethers for the removal of methyl, ethyl, isopropyl, and benzyl groups. A variety of functional groups such as alkenyl, allyl, amide, cyano, formyl, keto, nitro, and halogen are well tolerated under the optimum conditions. Partial hydrodebromination was observed during the demethylation of 4-bromoguaiacol, and was resolved using excess DMSO as an acid scavenger. This convenient and efficient procedure would be a practical tool for the preparation of catechols.

Supporting Information