Bicyclo nona-2,6-diene synthesis

Silver trifluoroacetate is used in a one step synthesis of bicyclo[3 2 2]nona-6,8-diene-3-one from 2-methoxyallyl bromide and benzene [50] (equation 23) Analogous reactions of toluene, p-xylene, and mesitylene yield the corre spending substituted bicyclo[3 2 2]noiia-6,8-diene-3-ones [50]... 

Although small in number, the investigations summarized above show that the Cope rearrangement of 7-(l-alkenyl)bicyclo[4.1.0]hept-2-enes is an effective method for the synthesis of usefully functionalized bicyclo[3.2.2]nona-2,6-dienes. 

A highly stereoselective total synthesis of racemic sesquicarene, a sesquiterpene analogous to d -carene was accomplished by the photochemical transformation of a bicyclo[3.3.2]nona-3,6-dien-2-one. ... 

Surprisingly, asymmetric inductions became much more modest as soon as the catalyst deviated from these structural features. For example, Frejd et al. reported the synthesis of new organocatalysts based on a dibenzo-bicyclo[3.3.1]nona-2,6-diene framework (Scheme 24.13) that were tested in the same hetero-Diels-Alder reaction shown in Scheme 24.12. Although only modest, the best results were observed in the presence of the hydro g ketone 31 (up to 52% ee), which was more active than 30 or 32 and also than chiral monodentate alcohols (33, 34 and 35). The authors speculated that in the transition state there was the coordination of the aldehyde in a cleft in the... 

Bicyclo[5,3,0]dec-l(7)-en-2-one was obtained by anodic oxidation of bicyclo-[4,4,0]decane-l,6-diol in methanol containing tetraethylammonium p-toluenesul-phonate. The dicarboxylic acid (68), used in the synthesis of methymycin, was obtained by oxidative cleavage of 8-formylbicyclo[4,2,l]nona-2,4-dien-7-one. Autooxidation of (-t-)-car-3-ene in the presence or absence of cobalt stearate gave a complex mixture of products including eucarvone (up to 11.5 %) and 3,6,6-trimethylcyclohepta-2,4-dienone (up to 48 %). 3-Methylene-4-cholestene gave a 40% yield of 3,3-diazido-A-homochoIest-5-ene when treated with Pb(OAc)4 (N3) . ... 

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