A process can prepare a 3-glycidyloxypropylalkoxysilane of formula (I), (R′)O—(CH2)3—Si(OR)3 (I), where R groups are independently a methyl or ethyl group and R′ represents an H2C(O)CHCH2— group. The process includes reacting (i) a functionalized alkene of formula (II), (R′)O—C3H5 (II), where R′ represents an H2C(O)CHCH2— group, with (ii) at least one hydroalkoxysilane of formula (III), HSi(OR)3 (III), where R groups are independently a methyl or ethyl group. The reacting takes place in the presence of (iii) a Karstedt catalyst or a catalyst having hexachloroplatinic acid as a homogeneous catalyst, and (iv) 2-ethylhexanoic acid, isononanoic acid, or both. The process further includes obtaining a product of the reacting.