A Nazarov-Ene Tandem Reaction for the Stereoselective Construction of Spiro Compounds.

ABSTRACT: The different reactivity of trienones under Lewis and Brønsted acids catalysis was investigated, resulting in distinct cyclization products and carbon backbones that originated either from a conjugate Prins cyclization or an interrupted Nazarov cyclization. In particular, an unprecedented Nazarov cyclization tandem reaction is presented, terminating the oxyallyl cation by an ene-type reaction, and leading stereoselectively to bicyclic spiro compounds. The terminal olefin of this motif represents a useful handle for further functionalization, making it a strategic intermediate in total syntheses. The tandem Nazarov/ene cyclization was shown to be preferred over a Nazarov/[3+2] tandem reaction for all our substrates, independent of chain length. Deuteration studies further support the mechan

SUBMITTER: Etling C 

PROVIDER: S-EPMC8361765 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature