SYNTHESIS AND STEREOCHEMISTRY OF SOME NEW BROMINATED SPIRO 1,3-DIOXANES

New dibrominated spiro 1,3-dioxanes have been obtained by a regio- and diastereo-selective reaction between six-membered ring spiro compound s and bromine. Studies on the stereochemistry of these brominated comp ounds, exhibiting a 1,5-dioxaspiro[5.5]undecane skeleton, were carried out by NMR methods in solution and by the solid-state molecular struc ture of four compounds established by single-crystal X-ray diffractome try. The diasteroselectivity of the bromination was explained by the a symmetric Induction of chiral carbon atoms and the chiral spiro skelet on.