Undecenyl resorc[4]arene in the chair conformation as preorganized synthon for olefin metathesis?

RSC Advances Pub Date: 2013-07-24 DOI: 10.1039/C3RA42943A

Abstract

Tetramerization of (E)-2,4-dimethoxycinnamic acid ω-undecenyl ester with ethereal BF3 gave three stereoisomers 1a, 1b, and 1c, which were assigned as the chair, cone, and 1,2-alternate conformations, respectively. The chair conformation of 1a was confirmed by X-ray diffraction analysis, which also showed a peculiar self-assembly behavior in the crystal lattice, forming intercalated hydrophilic and hydrophobic layers (6–7 ? thickness) as a consequence of strong CH–π interactions. Undecenyl resorc[4]arene 1a, which featured the simplest pattern of substituents, was submitted to olefin metathesis using the second-generation Grubbs complex as the catalyst. Depending on the reaction conditions, different products were isolated: a bicyclic alkene 2a (46%), a linear dimer 3a (5%), and a cross-linked homopolymer P1a (44%).

Graphical abstract: Undecenyl resorc[4]arene in the chair conformation as preorganized synthon for olefin metathesis
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