RING TRANSFORMATION OF PHOSPHORUS-CONTAIN ING HETEROCYCLES .15.

Some phospholene oxides were transformed into the corresponding phosph ine-boranes. The reaction of a 2-phospholene-borane with dichlorocarbe ne gave the phospholene- and the phospholane-dichloromethyl-boranes as the major products, and the cyclopropane derivative as the minor comp onent. A similar reaction of 3-phospholene-boranes afforded only the p hopholene- and the phospholane-dichloromethyl-boranes. A phosphabicycl ohexane-borane was synthesized from the P-oxide by change in the funct ionality. The dihydrophosphinine-boranes were prepared by cyclopropane ring opening of a phosphabicyclohexane, or by change in the functiona lity of the dihydrophosphinine oxides. The reaction of dihvdrophosphin ine-boranes with dichlorocarbene did not result in the formation of th e desired phosphepine. This species was eventually synthesized by chan ge in the functionality of the P-oxide. The preparation of unsaturated phosphine-boranes was usually complicated by reduction side-reactions .