反应详情

n-Butyllithium (2.5 M soln in hexane, 1.78 mL, 4.44 mmol) was added dropwise to a stirred solution of dichloromethane (0.36 mL, 5.55 mmol) in THF (8 mL) at −100° C. under argon atmosphere; at the end of the butyllithium addition, a white microcrystalline precipitate (LiCHCl2) became evident. After 30 min, a solution of 13a (1.00 g, 3.70 mmol) in THF (8 mL) was slowly added at the same temperature. The white precipitate disappeared and the mixture allowed to gradually reach room temperature overnight. The resulting solution was concentrated under reduced pressure. The crude was treated with petroleum ether (50 mL), and the resulting white inorganic precipitate was filtered off and washed with abundant petroleum ether. Solvent evaporation in vacuo afforded (+)-pinanediol (1S)-1-chloro-2-phenylethaneboronate, used as such for the subsequent reaction.

1. customallowed to gradually reach room temperature overnight
2. concentrationThe resulting solution was concentrated under reduced pressure
3. additionThe crude was treated with petroleum ether (50 mL)
4. filtrationthe resulting white inorganic precipitate was filtered off
5. washwashed with abundant petroleum ether
6. customSolvent evaporation in vacuo