u03b1 h 4 49 1h t j 7 0 hz 22 h 6 18 and 6 30 2h each d j 8 3 hz 6 and 7 h 7 3 7 5 7h br m ar h 7 79 2h d j 8 2 hz ar h to a stirred solution of tosylate 3 4 9 mg 5 u03bcmol in 1 1 v v acetone 2 butanone 200 u03bcl was added calcium carbonate 1 mg 10 u03bcmol followed by sodium iodide 3 7 mg 25 u03bcmol the resultant mixture was stirred and heated for 80 h at 55 u00b0 c under argon by which time no starting material remained the reaction mixture was poured into water 10 ml and extracted with ethyl acetate 2 u00d7 10 ml the combined organic layers were washed with 1 na 2 so 3 and water dried na 2 so 4 and evaporated the residue was separated by preparative hplc 6 2 mm u00d7 25 cm zorbax silica column using 3 ethyl acetate in hexane as an eluent pure e 20 22 dehydro compound 4 2 2 mg 55 collected at 52 ml was obtained as a foam 1 h nmr cdcl 3 500 mhz u03b40 087 and 0 109 3h and 3h each s 2 u00d7 sime 0 571 6h q j 8 hz 3 u00d7 sich 2 0 658 3h s 18 h 3 0 888 9h s si t bu 0 950 9h s 26 and.