New R dbr 011 tbe S temmktd'tyofKetoketmeDimeriudoes Alkylation of 2, Uisubstituted 1, 3- cyclobutanediones results in tetraalkylcyclobutanediones with nutts-positioned large resi- dues. Thermal dimerization of hpropylmethylketene gives cis-dimer 4r as major product, whereas methylneopentyketene yields more of the hum-isomer 5b. The results an discussed in connection with a L2,+ $?. I process.
