engleski

Stereoelectronic control of Grignard additions of vinylmagnesium bromide to 1-methyl- and 3-methylpentacyclo[5.4.0.02, 6.03, 10.05, 9]undecane-8, 11-diones and to1-methylhexacyclo[10.2.1.02, 11.04, 9.04, 14.09, 13]pentadeca-5, 7-diene-3, 10-dione

Grignard addition of excess vinylmagnesium bromide to 1-methyl- and 3-methylpentacyclo[5.4.0.0(2, 6).0(3, 10).0(5, 9)]undecane-8, 11-diones (1a and 1b, respectively) and to 1-methylhexacyclo[1.0.2.1.0(2, 11).0(4, 9).0(4, 14).0(9, 13)]pentadeca-5, 7-diene-3, 10-dione (4) each proceed regiospecifically to afford a single hemiketal adduct (i.e., 2a, 3a, and 5a, respectively). The structure of each of the three reaction products was established unequivocally via application of X-ray crystallographic methods. Relative energies for the model transition states obtained from geometry optimizations at the Hartree-Fock level of theory in basis set 3-21G(d) indicate that these reactions are kinetically controlled.

Grignard additions; cage compounds

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