Silicon-directed acid ring-opening of allyltrimethylsilane oxide. X-ray structures of 3-triisopropylsilyl-2-(2,4-dinitrobenzoyloxy)-1-propanol and 3-triisopropylsilyl-2-(2,4,6-trinitrobenzoyloxy)-1-propanol

Abstract

Allyltrimethylsilane oxide 5 undergoes regiospecific ring-opening with carboxylic acids in chloroform to give the hydroxy esters 6a– e. In polar solvents competing elimination results in the formation of allyl alcohol. Allyltriisopropylsilane oxide 17 undergoes analogous reactions as 5 in chloroform but does not undergo elimination in methanol or acetone. The X-ray structures of 18b and 18c reveal significant lengthening of the C–O (ester) bond (a remarkable 1.502(2) Å for 18c), these structural effects are due to strong σ C–Si– σ* C–O interactions, particularly for 18c.