A new method is described for effecting selective monofunctionalization of
CH2=CH)(8)Si8O12 2: reaction of 2 with triflic acid (TfOH) produces (TfOCH2
CH2)(CH2=CH)(7)Si8O12 3, which reacts with nucleophiles (e.g. H2O or 2-merc
aptopyridine) to produce (XCH2CH2)-(CH2=CH)(7)Si8O12 (4 X = OH, 5 X = SC5H4
N); acylation of 4 with p-O2NC6H4COCl affords (p-O2NC6H4CO2CH2CH2)(CH2=CH)(
7)Si8O12 6; catalytic hydrogenation of 4 affords (HOCH2CH2) Et7Si8O12 7.