Abstract Unhindered N,N′-diphenyltetramethylcyclodisilazane readily undergoes hydrolysis in the presence of catalytic amounts of acid or base. Under base conditions an intermediate diaminodisiloxane may be isolated. The more sterically congested hexaphenylcyclodisilazane is resistant to acid hydrolysis but is readily hydrolyzed in the presence of base. Hydrolysis of this substrate in the presence of fluoride ion gives rise to a number of fluorine-containing products.