9,9-Dimethyl-8,10-dioxapentacyclo[5.3.0.02,5.03,5.03,6]decane and naphthotetracyclo[5.1.0.01,6.02,7]oct-3-ene: new substituted [1.1.1]propellanes as precursors to 1,2,3,4-tetrafunctionalized bicyclo[1.1.1]pentanes

Two new substituted [1.1.1]propellanes have been generated from the corresponding bicyclo[1.1.0]butanes in either single-step () or four-step procedures (). The observed degree of double lithiation of the bicyclo[1.1.0]butanes is discussed in the context of DFT computational results. Addition reactions across the central C(1)–C(3) bonds of the propellanes were studied. Only the propellane gave the biacetyl addition product.