F. Toda, Nobuhiro Ooi
Jun 1, 1973
Citations
0
Influential Citations
7
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Treatment of 3,4-bis(diphenylmethyl)cyclobut-3-ene-1,2-dione (I) with bromine in ROH (R=H, Me, Et, and i-Pr) afforded 3,4-bis(diphenylmethylene)cyclobutane-1,2-dione (IV) and 3-diphenylmethyl-4-alkoxydi-phenylmethylcyclobut-3-ene-1,2-dione (III) in various ratios depending on the steric bulkiness of R of ROH. Acidification of a solution of III in KOH–MeOH, in which III exists in the form of enolate anion (VIII), afforded III and IV in various ratios depending on the steric nature of the substituent R. Bromination of IV in 99% acetic acid afforded 3,4-bis(hydroxydiphenylmethyl)cyclobut-3-ene-1,2-dione (XI). Although the bromination of XI with phosphorus tribromide afforded IV, that with bromine afforded the 2,5-dihydrofuran derivative (XVII). The reaction of I with o-phenylenediamine to afford azamethylenecyclobutane derivatives XXV and XXVI is described.