The mixture was concentrated under reduced pressure, and the concentrated material was resuspended in THF (11 mL).
After the synthesis reaction, the reaction mixture was concentrated to 300 μl with a concentrator (Amicon Ultra-15, 30,000 MWCO, Millipore-Japan, Tokyo, Japan).
Then the reaction mixture was concentrated in vacuo.
Upon completion, the reaction mixture was concentrated by evaporation under reduced pressure.
After cooled down to room temperature, the crude mixture was concentrated in vacuo.
Toluene (3 mL) was added; the reaction mixture was concentrated to dryness and then azeotroped with MeOH three times.
After 5 min, the reaction mixture was concentrated in vacuo, then was passed through a short silica gel column to remove PhI.
The obtained mixture was concentrated and kept overnight in refrigerator.
The reaction mixture was concentrated and allowed to cool.
The mixture was concentrated in vacuo to give 4.
Upon completion of the reaction, the mixture was concentrated under reduced pressure.
