(4-NO2)C6H4CHO in toluene byproducts: CH2CCOOCH(4-NO2-C6H4)C(CH3)(SiPh2(t-C4H9)OCH2); treatment of small excess (1.5 equiv.) of crude (SiPh2(t-C4H9)OCH2)(Me)CCCO2CH3(CH2B(OC(CH3)2)2) with (4-NO2)C6H4CHO in toluene at 80°C. for 16-120 h;