hz ch 2 so 2 3 60 m 1h chco 3 88 t 1h j 6 3 hz chn 4 80 d 1h j 8 4 hz cho 4 86 pent 1h j 4 3 hz cho 13 c nmr 75 mhz cdcl 3 d 20 0 8 21 0 9 26 5 5 26 6 ch 2 30 1 ch 2 32 9 6 34 4 ch 2 37 5 ch 2 38 4 3 44 6 4 47 8 7 48 5 1 53 2 10 54 1 c hco 60 2 chhg 65 5 2 79 3 cho 81 9 cho 172 7 co anal calcd for c 19 h 28 nso 4 hgcl c 37 87 h 4 68 n 2 33 found c 37 89 h 4 77 n 2 39 a solution of the bicyclic mercurial 8 178 mg 0 3 mmol aibn 59 mg 0 36 mmol in toluene 6 ml was stirred under argon and tributyl tin hydride 1 ml 3 6 mmol was added the solution was then stirred at rt overnight warmed between 70 900 for 1 hour left to cool to rt ccl 4 1 ml was added and the reaction stirred for 1 hour more after the reaction solution was separated from the mercury residues it was taken up in.