The molecular structure of (R,S)-[Al6But6(µ3-O)4{µ3-O2CCH2C(H)(Me)O}2]: evidence for the latent Lewis acid catalyzed polymerization of (R,S)-β-butyrolactone

The reaction of [ButAl(µ3-O)]6 with 2 equiv. of (R,S)-β-butyrolactone resulted in the formation of the alumoxane, (R,S)-[Al6But6(µ3-O)4{µ3-O2CCH2C(H)(Me)O}2], with a molecular structure consisting of two ring-opened lactone moieties inserted into, and bridging, the edge of the Al6O6 alumoxane. The role of this alumoxane in the latent Lewis acid catalyzed ring-opening polymerization of β-butyrolactone is discussed.