反应详情

温度

-15 °C

A reducing agent is prepared in the same manner as in Example 9 from a mixture of L-tert-leucine (721 mg), sodium borohydride (189 mg) and tetrahydrofuran (50 ml), and the reaction mixture is cooled to -15° C. To the mixture is added 2-(4-methoxyphenyl)-1,5-benzothiazepine-3,4(2H,5H)-dione (997 mg), and the acid listed in the following Table 1 is added thereto at 30 minutes and 2 hours thereafter (totality: 3.33 mmole), and the reaction is carried out at the same temperature. After confirming by HPLC that the starting compound is completely consumed, the mixture is treated in the same manner as in Example 9 to give (2S,3S)-3-hydroxy-2-(4-methoxyphenyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one. The yield, optical purity of the cis-compound and content of the trans-compound are as shown in the following Table 1.

1. additionis added
2. custom2 hours
3. customis completely consumed
4. additionthe mixture is treated in the same manner as in Example 9