The addition of dichloroketen to methylenecyclobutane: a new route to spiro[3,3]heptanes and spiro[3,2]hexanes
Abstract
In the addition of dichloroketen to methylene-cyclobutane, no non-classical ionic intermediates have been detected: a spiro[3,3]heptanone is obtained which can be reduced and ring-contracted, giving spiro[2,3]-hexane derivatives.