Ketones, reductive cleavage silyl enol ethers

Among other methods for the preparation of alkylated ketones are (1) Alkylation of silyl enol ethers using various reagents as noted above, (2) the Stork enamine reaction (10-69), (3) the acetoacetic ester synthesis (10-67), (4) alkylation of p-keto sul-fones or sulfoxides (10-67), (5) acylation of CH3SOCH2 followed by reductive cleavage (16-86), (6) treatment of a-halo ketones with lithium dialkylcopper reagents (10-57), and (7) treatment of a-halo ketones with trialkylboranes (10-73). 

Some examples of regioselective alkylations of simple ketones are presented in Scheme 1.6. These examples illustrate the most useful modes of enolate generation, including deprotonation (entries 3 and 4), enone reduction (entries 1, 2, and 5), and cleavage of silyl enol ethers (entries 6 and 7). 

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