Multiple ansa compound

A few other variations are included here to demonstrate the diversity of this class with regard to molecular shape. Vogtle et al. s multiple ansa compound (115, R = CH2CH2OCH2CH3), an unexpected product obtained from an attempt to synthesize biscalixarenes with aromatic linkers, has two bridges threaded through the macrocycle formed by joining the two calixarenes subunits [152]. Siegel et al. s... 

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