反应详情

To a stirred mixture of 1 g (4.34 mmol) of 1-benzyloxycarbonyl-2-t-butoxycarbonylhydrazine (Dutta et al., J.C.S. Perkin I, 1975, 1712-1720) in 30 ml of anhydrous methylene chloride 1.55 g (8.7 mmol) of N-bromosuccinimide was added at 0° C. and the stirring was continued for 1 hour with external cooling in an ice bath. The reaction mixture was washed with 10% aqueous sodium thiosulfate solution and saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate and evaporated to dryness in vacuo. The residue was redissolved in 15 ml of anhydrous ether, 0.57 g (8.7 mmol) of freshly distilled cyclopentadiene was added and the mixture was allowed to stay for I hour at room temperature. Evaporation to dryness under reduced pressure gave 0.77g (54% yield) of the title product as a colorless syrup; NMR (CDCl3) 1.44 (s, 9H, t-butoxy CH3); 1.7 (m, 2H, CH2 -7); 5.06 (m, 2H, CH-1,4); 5.15 (s, 2H, methoxy CH2); 6A (m, 2H, CH-5,6); 7.24 (m, 5H, aromatic).

1. additionwas added at 0° C.
2. temperaturewith external cooling in an ice bath
3. washThe reaction mixture was washed with 10% aqueous sodium thiosulfate solution and saturated aqueous sodium chloride solution
4. dry with materialdried over anhydrous magnesium sulfate
5. customevaporated to dryness in vacuo
6. dissolutionThe residue was redissolved in 15 ml of anhydrous ether
7. addition0.57 g (8.7 mmol) of freshly distilled cyclopentadiene was added
8. customto stay for I hour at room temperature
9. customEvaporation to dryness under reduced pressure