2-Cycloheptenone alkyl-substituted

Good stereoselectivity is observed in the addition of lithium dialkylcuprates to 4-, 5-, and 6-alkyl-substituted cycloheptenones. Stork has used the stereoselectivity of addition of functionalized cuprates to the conformationally rigid enone-lactone (104) to produce (on further modification) the trans-fused hydrindone (105) [equation (65)]. ... 

The acid chlorides of to-(2-thienyl) substituted butyric (122) and valeric acids (123), as well as the corresponding 5-alkyl-2-thienyl-substituted compounds, undergo internal Friedel-Crafts reaction (SnCl4,CS2) at the 3-position in 70-80% yield, to give the corresponding cyclohexenones (124) and cycloheptenones (125). ... 

In the presence of proton and/or Lewis acid and strong nucleophiles bicyclo[3.2.0]heptan-6-ones are converted to 3-substituted cycloheptanones (Table 15). Bicyclo[3.2.0]heptan-6-ones rearrange to give 3-iodocycloheptanones on treatment with iodotrimethylsilane. Zinc(II) iodide or mercury(II) halides as catalysts enhance the rate and the selectivity of the reaction.31 If a second, enolizable carbonyl group is present, an intramolecular alkylation may follow the ring enlargement under these reaction conditions.32 Consecutive treatment with tributyltin hydride/ 2,2 -azobisisobutyronitrile affords reduced, iodo-free cycloheptanones, whilst treatment with l,8-diazabicyclo[5.4.0]undecene yields cycloheptenones.33 Similarly, benzenethiol adds to the central bond of bicyclo[3.2.0]heptan-6-ones in the presence of zinc(II) chloride and hydrochloric acid under anhydrous conditions to form 3-(phenylsulfanyl)cycloheptanones.34... 

Professor Shibasaki has also investigated (J. Am. Chem. Soc. 125 15840,2003) Michael addition to prepare alkylated secondary centers in high enantiomeric excess. Addition of substituted acetoacetates to cyclohexenone and to cycloheptenone proceeds with high . With the more reactive cyclopentenone, the is slightly lower. 

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