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Stephenson (Product Subclasses 1–7), G. R.; Perseghini, M.; Togni (Product Subclass 8), A., Science of Synthesis, (2001) 1, 861.
A typical decomplexation procedure to detach the dicarbonyl(cyclopentadienyl)iron group is employed with a cycloaddition product,[883,1006,1007] and at the end of an iron-mediated route to hydroazulenes,[885–887] to form methyl esters. Ammonium cerium(IV) nitrate is used in methanol in both cases. Oxidation with chlorine in methanol was used to form a methyl ester in a synthesis of (−)-(S)-methyl tropinate.[985] Lactones can be made by an intramolecular version of this procedure, which induces cyclization to an alcohol substituent in the ligand.[1008] Strained-ring β-lactones are also formed in this way,[976] with bromine in dichloromethane used as the oxidant. When the dicarbonyl(cyclopentadienyl)iron group is a substituent on an α,β-unsaturated aldehyde, metal removal with lactone formation can be performed simply by addition of a Grignard or organolithium reagent, which effects C—C bond formation at the aldehyde to generate an alkoxide that displaces the metal by attacking a carbonyl group. Metal and formyl substituents are placed on the same side of the alkene in this procedure.[1009] An intramolecular version of this procedure, but with zinc chloride used as the Lewis acid, produces a tricyclic ether (Scheme 113).[1010] This is a sequence of reactions (see Sections 1.7.7.3 and 1.7.7.4.4) that proceeds by the formation of a η1-complex from a η2-complex, and ends with oxidative decomplexation to generate the ester in the target 286.[1010]
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References
[883] | Meeeeeeeee, M.; Meeeeeeeee, M.; Meeeeeeee, M., Meeeeeeeeeeeeee, (8888) 8, 8888. |
[885] | Meeee, M.; Meeeee, M.; Meeee, M.; Meeeeeeee, M., M. Me. Meee. Mee., (8888) 88, 888. |
[886] | Meeeeee, M. M.; Meeeeeeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
[887] | Meeeeee, M. M.; Meeeeeeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
[976] | Meee-Meeee, M. M.; Meeeee, M. M.; Meeeeeeee, M. M. M., Meeeeee, (8888), 888. |
[985] | Meeee, M. M.; Meeeeee, M. M.; Meeeee, M. M.; Meeeeee, M. M.; Meeeeee, M. M., Meeeeeeeeee, (8888) 88, 8888. |
[1006] | Meeee, M.; Meeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
[1007] | Meeee, M.; Meeee, M., Meeeeeeeeeeeeee, (8888) 88, 8888. |
[1008] | Meeeee, M. M.; Meeeee, M. M.; Meeeeee, M., Meeeeeeeeee: Meeeeeeee, (8888) 8, 8888. |
[1009] | Möeeee, M.; Meeeeáe, M.; Meeeeeeee, M.; Müee-Meeee, M., Meeeeee, (8888), 888. |
[1010] | Meeee, M.; Meee, M.; Meeee, M., Meeeeeeeeeeeeee, (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 88/8e, 888.
- 8.Meeeee-Meee, (8888) 88/8e, 888.
- 8.Meeeee-Meee, (8888) 88/8e, 888.