Abstract4,4‐Dimethoxy‐2,5‐cyclohexadienones 9–14 were prepared from the corresponding hydroquinone monomethyl ethers by oxidation with thallium trinitrate in methanol. Irradiation of solutions of 9–13 in methanol with a broad band of UV light centered at 350 nm in a Rayonet reactor afforded 2‐cyclopentenone derivatives 15–19 in moderate to excellent yields, whereas irradiation of 14 in methanol gave phenol 8 along with other unidentified products. Irradiation of 11–14 in benzene yielded substituted phenols. The plausible reaction pathways for the product formation are discussed.
THE PREPARATION OF CHIRAL SALICYLALDEHYDES BASED ON KAGAN'S ETHER
作者:Michael Harmata、Yanhong Wu、Mehmet Kahraman、Christopher J. Welch
DOI:10.1081/scc-100106046
日期:2001.1
Two related routes to chiral salicylaldehydes which are derivatives of Kagan's ether have been developed. One route which is particularly simple begins with 2,6-diallylphenol. Facile conversion to a substituted benzofuran and assemblage of the basic framework of Kagan's ether is followed by an ozonolysis of the benzofuran ring to reveal the hydroxyaldehyde functionality characteristic of salicylaldehydes