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III. Migration of Aldehydo Groups

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    24055

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    A possible fate for an alkoxy radical formed by cyclization is ring opening to produce a radical dif­ferent from the one that initially formed the ring.4,13–17 A new direction in ring opening is likely if it produces a more stable radical. In the reaction shown in Scheme 8 such a situation exists.14,15 Ring opening of the alkoxy radical 20 gives the resonance-stabilized, benzylic radical 21 rather than the unstabilized radical 19 that reacted to produce the ring system. This alternative ring opening (20\(\rightarrow\)21) completes an addition-fragmentation sequence that causes migration of the aldehydo group.

    This page titled III. Migration of Aldehydo Groups is shared under a All Rights Reserved (used with permission) license and was authored, remixed, and/or curated by Roger W. Binkley and Edith R. Binkley.