146173-87-7Relevant academic research and scientific papers
Photoinduced Molecular Transformations. Part 135. New Synthesis of Taiwanin C and Justicidin E based on a Radical Cascade Process involving β-Scission of Alkoxy Radicals generated from 3- and 8-Aryl-1-ethyl-1,2-dihydrocyclobutanaphthalen-1-ols prepared by Thermolysis of (Z)-tert-...
Kobayashi, Kazuhiro,Kanno, Yoshikazu,Seko, Shinzo,Suginome, Hiroshi
, p. 3111 - 3118 (2007/10/02)
A new general synthesis of naturally occuring phthalide lignans, based on a radical cascade process triggered by a regioselective β-scission of the alkoxy radicals generated by photolysis of the hypoiodites of 8-aryl-1-ethyl-1,2-dihydrocyclobutanaphthalen-1-ols, is described.Two phases are involved in the present synthesis of phthalide lignans; the first is a new general synthesis of tert-butyl 4-aryl-3- and 4-aryl-8-aminonaphthalene-2-carboxylates by an electrocyclic reaction of o-quinonedimethides thermally generated from (Z)-tert-butyl 3-amino-3-(bicycloocta-1,3,5-trien-7-yl)propenoates; the second is a transformation of the protected 4-aryl-3-aminonaphthalene-2-carboxylic acids into the phthalide lignans.This latter phase involves their successive conversions into 3- and 8-arylcyclobutanaphthalen-1(2H)-ones via the formation of a benzyne intermediate, and then into 3- and 8-aryl-1-ethyl-1,2-dihydrocyclobutanaphthalen-1-ols, followed by β-scission of the alkoxy radicals generated by photolysis of their hypoiodites, generated in situ with the mercury(II) oxide-iodine reagent in benzene.Simultaneous syntheses of the naturally occuring phthalide lignans taiwanin C and justicidin E were thus achieved.
