A Concise Route To The Azaspirodecane Moiety Of Halichlorine And Structurally Related Alkaloids.

[reaction: see text] A tandem Michael addition-enolate alkylation followed by Dieckmann cyclization and Beckmann rearrangement provided the corresponding [5.4.0] azaspirobicyclodecane, a key intermediate in our synthetic route to the marine alkaloid halichlorine (1).71617-