Orthogonally protected dialkynes

Several CSiMe3 and CGeMe3 protected dialkynes have been synthesized and regioselectively deprotected by protodesilylation or protodegermylation. Catalytic amounts of CuBr in THF/MeOH or in aqueous acetone lead exclusively to protodegermylation. The Me3Si group was removed with KF/[18]-crown-6 in aqueous THF without affecting the GeMe3 group. CSiMe3 protected propargyl ethers are also selectively cleaved with K2CO3 in THF/MeOH.