Kleine Ringe, 87. Suche nach alternativen Wegen zum Tetra‐tert‐butyltetrahedran; Synthese sterisch überladener Verbindungen

Small Rings, 87. – Search for Alternative Routes to Tetra‐tert‐butyltetrahedrane; Synthesis of Sterically Overcrowded Molecules Ketene 3 can be isomerized to triclopentanone 2 by treatment with silica gel. Thus, the yield of tetrahedrane 5, which is formed upon irradiation of 2, has been improved. On the other hand, diazoketone 10 cannot be used as a precursor for 2. This failure is due to steric hindrance. For the same reason cyclobutadiene 4 is a very poor candidate for Diels‐Alder cycloadditions.