Composés multispiranniques, dérivés de la di-isopropylidène-2,4 cyclobutanone

Abstract

In the action of diazomethane on di-isopropyliden-cyclobutanone (DiPC), three products showing a multispirannic structure were isolated : the first one C12H18ON4, Fus. 118-20° C, which is to be considered as generated by two consecutive cyclo-additions, is the dispiro [bis (4,4-dimethyl, 1-pyrazolin, 3-yl) 2', 4'] cyclobutanone ; the second one, C13H20ON4, Fus. 101-3° C, generated from 2 by the further reaction of diazomethane getting the methylene radical fixed on the carbonyl group, may be called trispiro [bis (4,4-dimethyl, 1-pyrazolin, 3-yl) 2', 4' 2-oxirane, 1'] cyclobutane (5) and the last one, Ci3H2oON4, Fus. 149-51° C, which is an isomer of the former, resulting from the insertion of a methylene group in the cyclobutanone ring, is the dispiro [bis (4,4-dimethyl, 1-pyrazolin, 3-yl) 2', 4'] cyclopentanone (4). Rather unexpected was the decarbonylation, by U.V. photolysis, of 2, getting the unknown, CnHiSN4, Fus. 128-30° C, which was the dispiro [bis (4,4-dimethyl, 1-parazolin, 3-yl) 2', 4'] cyclopropane. Finally, it was also possible with the COREY reactant acting on D/PC to synthétisé a mixture of both cis, Fus. 72-3° C, and trans, Fus. 101-2° C, isomers of the dispiro [bis (2,2-dimethyl, 1-cyclopropyl) 2', 4'] cyclobutanone, CiiHisO, in quantitative yield. Spectroscopic data are given to assess the structure of the compounds described.