A total of eighteen linear polysiloxanes of general formula Me3SiO‐(MeSi(E)O)x(MeSi(H)O)ySiMe3 (E = —(CH2)nester; x+y = 40) have been prepared by the platinum catalysed addition of CH2=CH(CH2)n‐2 ‐ester to Me3SiO‐(MeSi(H)O)40SiMe3 under anhydrous conditions. Polymers containing the ester functionalities—(CH2)3CO2R(R = Me, CF3, Et, Pr, and CH2COMe),—(CH2)3‐CHMeCO2Et, —(CH2)2CH(CO2Me)2, —(CH2)3CH(CO2Et)2, ‐(CH2)3CO2CH= CHCO2CH2CH=CH2 and —(CH2)3CO2C6H4CO2 CH2CH=CH2 have been characterised by analysis and 1H and 13C NMR spectroscopies. Factors affecting Markownik off versus anti‐Markownikoff addition of allyl acetate to this polymethylsiloxane have also been explored.