Abstract The preparation and characterization of five new hydroxyalkyl silicon compounds,( hydroxymethyl) pentamethyldisilane,(α-hydroxyethyl)-and (β-hydroxyethyl) pentamethyldisilane and α-hydroxyethyl)-and (β-hydroxyethyl)-tert-butyldimethylsilane are described. In hydroboration of vinylsilanes used here, all the organosilicon substituents attached to the vinyl group, ie,(CH 3) 3 Si,(CH 3) 3 SiSi (CH 3) 2 and (CH 3) 3 CSi (CH 3) ...