Silanes of the formula R1R2R3SiH add to acetals of acrolein with platinum catalysts to form R1R2RaSiCH2-CHzCH (0R) z. lv2 However, no aldehydes have been prepared from these acetals and characterized except for 3-triethyl~ ilylpropanal~ and 3- diethylmethylsilylpropanal. We wished to prepare compounds having siloxane structures substituted with propanal groups and to study the chemistry of the aldehyde group in such ...