- Resolution and Absolute Configuration of Bicycloocta-2,6-diene-2-carboxylic Acid
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An efficient resolution of the title acid (1) by using (+)- and (-)-α-phenethylamine is described.The (+) acid was determined to be 1S by chemical correlation through (+)-cis-bicyclooctan-2-one (3) with (+)-cis-bicyclooct-7-en-endo-2-ol (4) where the absolute configuration is known to be 1R.The 1R configuration for (-)-3 was consistent with the negative Cotton effect observed for this ketone.
- Whitesell, James K.,Minton, Mark A.,Felman, Steven W.
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p. 2193 - 2195
(2007/10/02)
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- ACID CATALYZED RING CONTRACTIONS IN ENDO-2,8-TRIMETHYLENE-CIS-BICYCLOOCTYL CATIONS TO METHYLPERHYDROTRIQUINACENES. ONE OF THE METHYL EXTRUSION PROCESSES IN THE TRICYCLOUNDECANE REARRANGEMENT
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Sulfuric acid catalyzed ring contractions with extrusion of a methyl group were examined for alcohol and olefin derivatives (28-31) of endo-2,8-trimethylene-cis-bicyclooctane (11), which was one of the two possible progenitors, among altogether 69
- Fujikura, Yoshiaki,Takaishi, Naotake,Inamoto, Yoshiaki
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p. 4465 - 4478
(2007/10/02)
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- Acid catalyzed ring contractions in endo-2,8-trimethylene-cis-bicyclo[3.3.0]octylcations to methylperhydrotriquinacenes. One of the methyl extrusion processes in the tricycloundecane rearrangement
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Sulfuric acid catalyzed ring contractions with extrusion of a methyl group were examined for alcohol and olefin derivatives (28-31) of endo-2,8-trimethylene-cis-bicyclo[3.3.0]octane (11), which was one of the two possible progenitors, among altogether 69 isomers, for methylperhydrotriquinacenes (6, 7 and 12), the only methyltricyctodecane intermediates found so far, in the tricycloundecane rearrangement. Only minor amounts (1.6-2.0%) of methylperhydrotriquinacenes were formed from these reactants 28-31, and the results support the earlier theoretical conclusion that the methyl extrusions were in general energetically quite unfavorable processes owing to the formation of primary carbinyl cations at the expense of more stable secondary bridge or tertiary bridgehead ones. Reaction pathways for these precursors 28-31 were discussed with reference to those of perhydrotriquinacene 2-carbinyl cations (33a's), which corresponded to some of the ring contraction product cations from 28-31.
- Fujikura, Yoshiaki,Takaishi, Naotake,Inamoto, Yoshiaki
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p. 4465 - 4477
(2014/12/10)
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