Macrocycles containing tin. Syntheses of symmetrical macrocycles containing two or four diphenylstanna units

Article abstract of DOI:10.1021/om00079a003

The syntheses of macrocycles containing two diphenylstanna moieties, c-[Ph₂Sn(CH₂)_n-]₂ (1, n = 4, 5, 6, 8, 10, 12), and four diphenylstanna moieties, c-[Ph₂Sn(CH₂)_n-]₄ (2, same n), are reported. α,ω-Bis-(bromomagnesio)alkanes reacted with Ph₃SnCl to give α,ω-bis(triphenylstannyl)alkanes which upon treatment with HBr gave α,ω-bis(bromodiphenylstannyl)alkanes 4. Compounds 4 reacted with the corresponding chain length α,ω-bis(bromomagnesio)alkanes to give 1 and 2. Alternatively, good yields of 1 (n = 4, 5, 6, 8) were obtained by converting 4 to dilithium reagents 7 which were allowed to react with α,ω-dibromoalkanes. Good yields of 2 (n = 4-6) were obtained by first treating 4 with Cl(CH₂)_nMgBr to give dichlorides which were then allowed to react with 7 in a second step. Purifications of the macrocycles and several synthetic intermediates were effected by preparative reverse-phase chromatography. The macrocyclic products were characterized by NMR spectroscopy, molecular weight determinations, and elemental analyses.