Through a double cyclization triplet carbonylcarbenes add smoothly to double bonds in the δ and ε position, but do not react intramolecularly with C-H bonds (see scheme). The addition reaction fails if the keto group is replaced with an ester group.
Tandem RCM of Dienynes for the Construction of Taxol-Type Carbocyclic Systems
作者:Rebeca Garcia-Fandiño、Eva M. Codesido、Eduardo Sobarzo-Sánchez、Luis Castedo、Juan R. Granja
DOI:10.1021/ol036062m
日期:2004.1.1
[GRAPHICS]Tandem ring-closing metathesis of hydrindanone dienynes allows access to taxosteroids, a new class of compounds that combine the [5.3.1] carbocyclic system of taxanes with rings C and D of the steroid skeleton.
Fairfax David J., Austin David J., Xu Simon L., Padwa Albert, J. Chem. Soc. Perkin Trans. 1, (1992) N N21, S 2837-2844
作者:Fairfax David J., Austin David J., Xu Simon L., Padwa Albert
DOI:——
日期:——
The intramolecular acylation of some hex-, hept-, and oct-enoic acids
作者:M. F. Ansell、J. C. Emmett、R. V. Coombs
DOI:10.1039/j39680000217
日期:——
acids. Intramolecular acylation of these acids in the presence of trifluoroacetic anhydride is shown to be dependent on the structure and stereochemistry of the acids. The formation of cyclohept-2-enone from hept-6-enoic acid is reported. Concentrated sulphuric acid in acetic anhydride is shown to convert hex- and hept-5-enoic acid into phenyl and o-tolyl acetate, respectively. Some improved syntheses
alkenyl C–H allylation by an exo-palladacycle intermediate is demonstrated, employing unactivated (Z)-alkenes and allyl carbonates. With the use of an 8-aminoquinoline (AQ) derived amide as the directing group, the N,N-bidentate-chelation-assisted C–H activation protocol proceeded under mild and oxidant-free conditions with excellent selectivity. The utility of this approach is demonstrated by the preparative