Photolysis of β-pinene and dodecamethylhexasilane (2) followed by methanol quenching gave the allylsilane5and the methoxysilane6. The intermediacy of the silirane7was proposed. Photolysis of α-pinene and2gave6only. The formation of another silirane15as intermediate was verified by deuterium labelling experiment. The potential of silylene chemistry in organic synthesis was examined.