RAMBERG-BACKLUND REARRANGEMENT VS. BETA-ELIMINATION OF HALOFORM FROM TRICHLORO AND TRIFLUOROMETHYL SULFONES

A new and convenient method for the preparation of trichloro and trifl uoromethanesulfinates is described. These esters readily undergo rearr angement to the corresponding sulfones at room temperature, in high yi elds. In contrast to trichloromethyl sulfoxides which undergo base-ind uced beta-elimination of chloroform to sulfines, the corresponding sul fones undergo an unusually facile Ramberg-Backlund rearrangement with formation of dichloromethylene products. Replacement of CCl3 by CF3 re sults in complete loss of reactivity, even under drastic basic conditi ons. (C) 1998 Elsevier Science Ltd. All rights reserved.