Annulation Tactics of cis‐syn‐cis Triquinanes by Allylsilanes: Application of Hosomi‐Sakurai Reaction Conditions.

A stereoselective [3+2] cycloaddition approach to functionalized pentaquinanes starting from cis‐syn‐cis triquinanes, derived from Cookson's diones, is reported. This transformation involves generation of six new stereocenters in a single step leading to cis‐anti‐cis‐syn‐cis‐anti‐cis polyquinane systems. Our method prevents transannular cyclizations which are prevalent in these moieties. The structure and stereochemistry of target molecules are well‐characterized based on NMR data and X‐ray diffraction studies. [ABSTRACT FROM AUTHOR]