The prior art required specialized substrates or reaction conditions to be
used to manufacture polysubstituted cyclobutane compounds and
polysubstituted cyclobutene compounds, and the method had poor
generality. The type or quantity of the catalyst or solvent used was also
problematic in the industrial manufacture of polysubstituted cyclobutane
compounds. The present invention provides a method for manufacturing a
polysubstituted cyclobutane compound with high stereoselectivity that has
low environmental load (is ecologically advantageous) and is applicable
to industrial manufacturing from the standpoint of operation, substrate
generality, catalyst, solvent, and efficiency. A polysubstituted
cyclobutane, a cyclobutene, and a bicyclo[4.2.0]octane compound can be
manufactured efficiently, stereoselectively, and in an ecologically
advantageous manner by causing a Bronsted acid to act on a mixture of an
enol ether compound or 2-siloxydiene compound with an alkene or alkyne
compound in which a carbonyl group is substituted at the 1-position in a
non-aqueous solvent or without a solvent.