4,4 ,5,5 -Tetrahydroxy-1,1 -binaphthyl

Not long thereafter, Tarnowski and Cram reported the first example of a hinged bis-crown ether. The compound was prepared in the usual Williamson reaction by heating a mixture of 2,2, 3,3 -tetrahydroxy-l, r-binaphthyl with pentaethylene glycol ditosylate and KOH in aqueous THF solution. The product (mp 159.5—161°) shown in Eq. (3.30) was obtained in 30% yield. This compound was shown to complex bis-ammonium cations of several varieties . 

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