Transmission of substituent effects through unsaturated systems Part 71. Influence of substituent on infrared and 13C NMR properties in rigid cisoid and transoid Conformations of α-enones

Synthesis and structure of some (E)-ferrocene-methylenecycloalkanones and their benzylidene analogs

“…The 1 H and 13 C NMR data and characteristic IR frequencies of the new compounds are given in Tables 1 and 2 and they prove the expected structures straightforwardly. Only a few additional remarks are necessary.…”

“…In the monosubstituted cyclanones 5 the cinnamoyl moiety is distorted even in the molecules of 5a with 5-membered ring: in the solid state the plane of the aryl ring deviates from that of the C=C double bond by 23 º . 28 Similar conclusions could be drawn from the 13 C NMR investigation of a series of E-(4'-X-benzylidene)cyclohexanones. 13 The similar spectral characteristics of 5 and 3 reflect a similar stereostructure for the corresponding 3.…”

“…25 For spectroscopic comparisons we have also prepared the corresponding E-2-benzylidenecycloalkanones (5a-c) 12,13,14 and E,E-dibenzylidenecycloalkanones (6a-c).…”

“…Compounds 5a-c (and their substituted derivatives) and 6a-c were prepared according to the methods described in the literature. 12,13,14 The isolated 4a and 4b had the melting points (250 o C (decomp.) and 179-181 o C, respectively) corresponding to the previously reported values.…”

“…The expected E-configuration of the compounds was based on comparisons of their 1 H and 13 C NMR data with previously published data of 5 and 6 5,13 and those of the respective E-2-benzylidene-and E-2-ferrocenmethylenebenzocyclanones. 10,11 The stereohomogeneous E,Econfiguration of 4a and 6a-c is proved by the symmetrical pattern of their NMR spectra.…”