Hydrolysis and Oxidation of a 1‐Boryl‐1‐silyl‐alkene. Molecular Structures of 9‐Hydroxy‐9‐borabicyclo[3.3.1]nonane and a Bicyclic Oxasilabora‐heptadecane B 2 (OSiPh 2 OSiPh 2 O) 3

Slow hydrolysis and oxidation of ( Z )‐9‐[1‐chlorodiphenylsilyl)‐2‐phenyl‐vinyl]‐9‐borabicyclo[3.3.1]nonane ( 1 ) afforded 9‐hydroxy‐9‐borabicyclo[3.3.1]nonane ( 2 ) and the bicyclic oxasilabora‐heptadecane B 2 (OSiPh 2 OSiPh 2 O) 3 ( 3 ), both of which could be isolated as crystalline materials and studied by X‐ray analysis. Molecules of 2 are associated in the crystal lattice by O‐H‐O bridging. The molecular structure of the diborabicyclo[5.5.5]heptadecane 3 is built by 12‐membered rings with the boron atoms in bridge head positions. The gas phase structures of 2 ( 2a ) and of the parent 3a , B 2 (OSiH 2 OSiH 2 O) 3 , were optimized at the B3LYP/6‐311+G(d,p) level of theory.