Permethyl cyclopentanone

The very high nucleophilicity of a-heterosubstituted a-lithiocyclopropanes and of a-lithioalkyl selenides, even those bearing two alkyl groups on the, carbanionic center, permits the stepwise construction of a cyclopentane ring possessing several quaternary centers in vicinal positions with respect to one another by two successive ring expansion reactions from a suitably functionalyzed cyclopropane 135,224) (Schemes 98, 101). This feature has been used by Fitjer2240 for the synthesis of permethyl cyclobutanone, permethyl cyclopentanone, and even permethyl cyclohexanone, as well as for the preparation of previously unknown permethylcyclohexane. 

Alkylation of Ketones. Ketones can be permethylated with iodomethane in DMSO containing solid KOH. Cyclobutanone, cyclopentanone, and indanone gave the corresponding tetramethyl ketones in 49, 90, and 75% yields, respectively. All reagents can be used without drying and KOH can be used as pellets or as a powder. ... 

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See also in sourсe #XX -- [ , , ]

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