Synthesis,structure, and spectral and photochemical properties of fulgides of the indole series with an adamantylidene fragment

New fulgides of the indole series with adamantylidene fragments were synthesized: 3-(adamant-2-ylidene)-2-1-(3-indolylethylidene)]succinic anhydride (I) and 3-(adamant-2-ylidene)-2-(3-indolylmethylene)]succinic anhydride (2). By means of electronic absorption and¹H NMR spectroscopy and X-ray diffraction analysis, fulgides1 and2 were shown to haveZ- andE-configurations, respectively. The photochemical properties of1 and2 were studied. It was shown that along withZ-E photoisomerization of these compounds, in solution they undergo a cyclization reaction to yield a colored photoproduct. Specific structural features of fulgide1 affecting its photochemical properties were discussed. The introduction of a bulky adamantylidene group decreases the extent of the conversion of compound1 into cyclic isomerC.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2301–2305, September, 1996.