Selective ring-rearrangement or ring-closing metathesis of bicyclo[3.2.1]octenes

Chem Commun (Camb). 2020 Oct 11;56(79):11779-11782. doi: 10.1039/d0cc04624h. Epub 2020 Sep 17.

Abstract

Explored was the competitive ring-closing metathesis vs. ring-rearrangement metathesis of bicyclo[3.2.1]octenes prepared by a simple and convergent synthesis from bicyclic alkylidenemalono-nitriles and allylic electrophiles. It was uncovered that ring-closing metathesis occurs exclusively on the tetraene-variant, yielding unique, stereochemically and functionally rich polycyclic bridged frameworks, whereas the reduced version (a triene) undergoes ring-rearrangement metathesis to 5-6-5 fused ring systems resembling the isoryanodane core.