Reaction of 1,exo-5-Dimethyl-3-oxo-exo-6-Carbomethoxy-tricyclo(5.2.1.0(2,6)dec-8- ene) with Ethanedithiol in the Presence of Boron Trifluoride Etherate. A Novel Fragmentation Process.

摘要

Reaction of the title compound, 1, with ethanedithiol in the presence of boron trifluoride etherate at -78 C is complete within five minutes. A single product, 2, was isolated from this reaction. The structure of 2 was established by careful analysis of its proton and carbon-13 NMR spectra. Proton and carbon-13 NMR chemical shift assignments are given along with 13C(1H) NOE values and spin-lattice relaxation times for all carbon atoms in 2. The formation of 2 in this reaction is rationalized in terms of a concerted reaction in which BF3-promoted cleavage of the C(1)-C(2) alpha-bond in the substrate occurs with concomitant stereospecific exo attack by ethanedithiol upon C(8) in the substrate. Organic chemistry. (jes)