Diastereoselective Michael reactions of (1R)-(+)-camphor methyl ketone enolates with nitro olefins

The reaction of the sodium enolate of the methyl ketone 2 with a range of nitro olefins proceeds readily to give the corresponding Michael adducts in good yields and diastereoselectivities. Subsequent oxidative cleavage of the acyloin moiety provides γ-nitroalkanoic acids along with (1R)-(+)-camphor, the chiral auxiliary of the process, which can be recovered and reused.