Synthesis 1990; 1990(7): 583-584
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage. 2,3-Dihydro-1,4-dioxin in Organic Chemistry. Part X. 1 A new Synthesis of 3-Hydroxy-3-cyclobutene-1,2-dione (Semisquaric acid)
17 September 2002 (online)
Cycloaddition of 2,3-dihydro-1,4-dioxin (
1) to 1,1-dichloroketene, generated from zinc and trichloroacetyl chloride by sonication, leads to 7,7-dichloro-2,5-dioxabicyclo[4.2.0]octan-8-one ( 2) which upon acid hydrolysis affords semisquaric acid (3-hydroxy-3-cyclobutene-1,2-dione, 3).