SYNTHESIS AND CRYSTAL-STRUCTURE OF DIMETHYL-4-ISOPROPYL-5-PHENYL)-3-PYRRYL-ETHYLIDENE (ISOPROPYLIDENE) SUCCINIC ANHYDRIDE

A new pyrryl fulgide, E-(alpha)-(1,2-dimethyl-4-isopropyl-5-phenyl pyr ryl-ethylidene (isopropylidene) succinic anhydride (1), was synthesize d, Molecular and crystal structures were determined. The characters of crystal structure of pyrryl fulgide (1) was discussed, It was found t hat the pyrryl fulgide (1) has a twisted structure between pyrrole rin g and the succinic anhydride portion, the dihedral angle between these two portions is 122.86(3)degrees, The phenyl ring located in the 5-po sition of pyrrole ring is not coplanar with the pyrrole ring, The dist ance between two reactive sites (C1 and C22 atoms) is 3.57 Angstrom wh ich is favorable for the photo-induced intramolecular cyclization of p yrryl fulgide (1).