Tandem Radical‐Addition–Aldol‐Type Reaction of an α,β‐Unsaturated Oxime Ether

The direct generation of boryl enamine 2 by radical addition to the chiral α,β-unsaturated oxime ether 1 (X=(1R)-camphorsultam, Bn=benzyl) followed by reaction with aldehydes gave rise to a tandem carbon–carbon bond-forming method, yielding lactones 3. The result is a novel asymmetric synthesis of γ-butyrolactones and γ-amino acids by way of both a radical and an ionic process.