Radical bromination of lH, 3H-naphtho [l, 8-cd] thiopyran 2, 2-dioxide (15) gave the corresponding monobromo sulfone 16 (48%), dibromo sulfone 12 (43%; cis/trans= 64/36), and tribromo sulfone 17 (5%). Ramberg-Backlund reaction of 12 was investigated under a variety of conditions with expectation of the formation of thiirene dioxide 11 from which generation of acenaphthyne (5) would be expected both thermally and photochemically. ...