ON THE CLAISEN REARRANGEMENT MECHANISM
55
3. Dewar, M.J.S. and Dougherti, R.C., The PMO Theory of
Organic Chemistry, New York: Plenum Press, 1975.
Translated under the title Teoriya vozmushchenii mole-
kulyarnykh orbitalei v organicheskoi khimii, Moscow:
Mir, 1977.
4. Bunina-Krivorukova, L.I., Yagodin, V.G., Marty-
nova, V.P., and Bal’yan Kh.V., Zh. Org. Khim., 1970,
vol. 6, pp. 991–995.
XV (retention time, 9.08 min), 174 (100), 145 (51), 131
(45), 133 (31); XVI (retention time, 9.85 min), 188
(100), 145 (44), 173 (30), 159 (34); XVII (retention
time, 9.69 min), 174 (100), 133 (58), 131 (37), 145
(19); XVIII (retention time, 10.11 min), 188 (100), 147
(50), 173 (34), 131 (23); XXIII (retention time,
11.19 min), 214 (100), 173 (53), 145 (50), 115 (32).
Thus, the calculation results indicate that the
Claisen rearrangement can proceed through the cyclic
six-centered transition state in the chair or boat confor-
mation or the π complex. On the one hand, the π com-
plex is a transition state that can result in the classical
products of the Claisen rearrangement, ortho-alke-
nylphenols, and on the other hand, the π complex seems
to be a key transition state for the formation of by-prod-
ucts of the Claisen rearrangement: para-alkenylphenols
and di- and trialkenylphenols. The process via a sol-
vent-separated ion pair and the release of the alkenyl
fragment to the bulk appears to be unlikely.
5. Bunina-Krivorukova, L.I., Rossiiskii, A.P., and
Bal’yan, Kh.V., Zh. Org. Khim., 1974, vol. 10, pp. 2461–
2462.
6. Shornik, N.A., Aleksandrova, E.K., and Bunina-
Krivorukova, L.I., Zh. Org. Khim., 1984, vol. 10,
pp. 2245–2247.
7. Schmidt, M.W., Baldridge, K.K., Boatz, J.A., Elbert, S.T.,
Gordon, M.S., Jensen, J.H., Koseki, S., Matsunaga, N.,
Nguyen, K.A., Su, S.J., Windus, T.L., Dupuis, M., and
Montgomery, J.A., J. Comput. Chem., 1993, vol. 14,
pp. 1347–1363.
8. Vittorelli, P., Winkler, T., Hansen, H.-J., and Schmid, H.,
Helv. Chim. Acta, 1968, vol. 51, pp. 1457–1461.
9. Hansen, H.-J. and Schmid, H., Tetrahedron, 1974,
vol. 30, pp. 1959–1969.
10. Bernardi, F., Epiotis, N.D., andYates, R.L., J. Am. Chem.
Soc., 1975, vol. 97, pp. 1334–1337.
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1. Rhoads, S.J. and Raulins, N.R., Org. React. Mech.,
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Helv. Chim. Acta, 1969, vol. 52, pp. 335–361.
DOKLADY CHEMISTRY Vol. 424 Part 2 2009