MEDIUM-SIZED GERMANIUM HETEROCYCLES: FIRST SYNTHESIS AND CONFORMATIONAL ANALYSIS OF A STERICALLY HINDERED EIGHT MEMBERED 12H-DIBENZO[d,g] [1,3,2]DIOXAGERMOCIN
摘要:
The first reported synthesis, characterization, and conformational analysis of the eight-membered germocin 2,2'-(4,6-di-(1)BuC(6)H(2)O)(2)GeMe(2) (3) is described. The VT H-1 NMR, C-13{H-1} NMR, and crystallographic data of 3 is consistent with a boat-chair conformation for the ring in both solution and the solid state. The free energy of activation (Delta G(299)*) for ring inversion is 55.6 kJ . mole(-1) (13.3 cal . mole(-1)).