Alkyl shifts in thermolyses. VI. Synthesis and characterization of the 2,4- and 4,5-dimethyl-1-carbethoxyspiropentanes and the 2-methyl-3-ethylidene-1-carbethoxycyclopropanes
Alkyl shifts in thermolyses. VI. Synthesis and characterization of the 2,4- and 4,5-dimethyl-1-carbethoxyspiropentanes and the 2-methyl-3-ethylidene-1-carbethoxycyclopropanes