Synchronized distortions of bicyclobutanes

The linear relationship between flap angle, θ, and bridging bond length, r₁₃, in bicyclobutanes, found empirically by Irngartinger through x-ray analysis, is reproduced by $\text{ab initio}$ STO-3G calculations. Additional distortions of the bicyclobutane geometry which are synchronized with flap angle variations are predicted.     

Numerische Behandlung des Gelenkvierecks

Ohne ZusammenfassungHerrn Professor Dr.Robert Sauer in München zu seinem 60. Geburtstag am 16. September 1958 gewidmet.     

Rearrangement of substituted tricyclo[2.1.0.02,5]pentan-3-ones

Treatment of 1,5-bis(hydroxymethyl)tricyclo[2.1.0.0^2,5]-pentan-3-one (III) with triphenyl phosphine and carbon tetrachloride results in deep-seated rearrangement to the keto furan, 3-oxybicyclo-[3.3.0]octa-1,4-dien-7-one, VI; the analogous reaction with carbon tetrabromide is normal and yields, the anticipated dibromide IV. Cyclopentadienone intermediates account for the latter reaction and for a dimer formed from 1,5-dimethyltricyclo[2.1.0.0^2,5] pentanone (Ia) upon treatment with iodine.