Comparative study on syntheses of 1,3,5-trimethoxy-1,3,5-triisopropylcyclotrisiloxane

1,3,5-Trimethoxy-1,3,5-triisopropylcyclotrisiloxane ( 2 ) was prepared from 1,3,5-triisopropyl-1,3,5-tri- o -tolylcyclotrisiloxane—( 1 ) according to three kinds of methods as follows: the dearylchlorination of 1 using HCl/AlCl 3 , which led to prepare 2 includes a very slight amount of aluminum species as impurities, the dearylbromination using Br 2 , which simultaneously brought unnecessary bromination without isolated 2 , and the dearylation using TfOH, which efficiently gave 2 of a high purity without metals of contamination.