Abstract The meso form of (RMeSiOH) 2 [R = Si(SiMe 3 ) 3 ] ( 2 ) was synthesized exclusively by hydrolysis of a diastereomeric mixture of (RMeSiCl) 2 ( 1 ). The novel cyclic metal disiloxides ( E )-(RMeSiO) 2 Ti(OEt) 2 ( 3 ) and [( Z )-(RMeSiO) 2 ] 2 Zr · HNEt 2 ( 4 ) are readily prepared from the reaction of meso - 2 with Ti(OEt) 4 and Zr(NEt 2 ) 4 , respectively. The results of X-ray structure analyses