Mercuri-desilylation of cyclopropylmethylsilanes such as 1 has been sh
own to occur with high regioselectivity. The cyclopropane ring-opening
followed by desilylation proceeds stereospecifically to afford the co
rresponding olefins in good yields. The mercuri-mediated opening of cy
clopropylmethyl alcohol analogues gives the opposite regioselectivity
and affords only the tetrahydrofuran through a 5-endo-trig cyclization
.