摘要：

(CH),, dienes (excluding stereoisomers) reported in Bal- aban's'O"trivalent multigraph of order 12, only six isomers (Balaban's designations 2-1-2-1, 2-1-2-5, 2-1-2-2, 2-1-2-9, 2-1-1-11 and 2-1-O-3)lobhave the symmetry, the two double bonds, and the one cyclopropane ring required by the above data (Figure 2). However, structures 2-1-2-1,2-1- 1-11,2-1-2-5,and 2-1-2-2 would require coupling between the olefinic protons, which was not observed. Structure 2-1-2-9 was eliminated because the two olefinic pairs should be coupled with the same bridgehead protons. As a matter of fact, the spin-decouplingstudies showed that the olefinic pairs in diene 12 were coupled with different bridgehead protons. These considerations, and also the direct gen- eration of diene 12 from decomposition of lithium and sodium salts of tosylhydrazone 15 both thermally and photochemically (see next part), convinced us that the structure of diene 12 was 2-1-0-3.Proton chemical shift and coupling constant assignments in diene 12 were made on the basis of spin decoupling experiments and are illustrated in Figure 3. The multiplet signal at 6 2.9 (2 H) was coupled to signals at 6 6.05 (2 H), 3.15 (2 H), and 1.91 (2 H).Thus, this was assigned to the bridgehead protons which are adjacent to the olefinic protons H9,10,the bridgehead protons H4,,a,nd the two bridge protons Hslz. This assignment was confirmed since the signal at 6 3.15 (2 H) was coupled to the signals at 6 5.45 (2 H), 3.35 (1H), and 2.9 (2 H). As a result, the signal at 6 3.15 was assigned to the bridgehead protons H4,,which are vicinally related to the olefinic protons H5,6,the single bridge proton HS,and the bridgehead protons H8and Hll. The maas spectrum of both pyrazoles 13 and 14 showed the expected molecular ion peak at mle 184. The absence of the bicyclononatriene unit of 8 was evidenced by major changes in the olefinic region of the `HNMR (in particular, the appearance of a two hydrogen singlet at 6 5.08-5.12 characteristic of the bridging ethylene group in bicyclo- [4.2.1]nonatrienes)11and by the absence of signals for the cyclopropane carbons (ca. 30) in the 13CNMR. The py- razole ring', gave rise to proton signals near 6 7.0 for both

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