日本大肚子孕妇交XXX,天天夜碰日日摸日日澡性色AV,女女女女女女BBBBBB毛,岳的大肥屁熟妇五十路99

熱線電話
產(chǎn)品新聞

Synthesis and Crystal Structures of Chiral

Abstract N-(2-Bromopropionyl)-O-benzyl-L-serine (BPBS) was prepared using 2-bromopropionic acid
and N-Boc-O-Bzl-L-serine as the starting reagents. BPBS underwent the intra-molecular ring-closing reac-
tion in DMF/Et
3
N solvent at 80 ℃for 9 h forming a mixture of two non-enantiomers, i.e. (3S,6S)-benzyl-
oxymethyl-6-methyl-morpholine-2,5-dione [(3S,6S)-BMMD] and (3S,6R)-BMMD with a yield of 70%. Two
optically pure enantiomers of BMMD, i.e. (3S,6S)-BMMD and (3S,6R)-BMMD were obtained via 4 opera-
tion circles of “solution-partial recrystallization” by means of a differential recrystallization method using
ethyl acetate as a solvent. The single crystals of the two isomers of BMMD were grown from ethyl acetate at
room temperature. The fine molecular structures of the two isomers were determined by X-ray diffraction
analysis of the single crystals.
Keywords (3S,6S)-benzyloxymethyl-6-methyl-morpholine-2,5-dione; (3S,6R)-benzyloxymethyl-6-methyl-
morpholine-2,5-dione; resolution; optical isomer; crystal structure


下一篇
日本大肚子孕妇交XXX,天天夜碰日日摸日日澡性色AV,女女女女女女BBBBBB毛,岳的大肥屁熟妇五十路99 CHINESE帅气男生自慰| 真人做爰高潮全过程毛片| 亚洲AV永久无码精品古装片 | 国产成人精品无码一区二区| 午夜天堂一区人妻| 黑人巨茎大战俄罗斯美女| 邪恶的江口君| 白嫩少妇BBW撒尿视频| 强壮的公次次弄得我高视频| 欧美《交换做爰》| 中文字幕人成无码人妻综合社区| 天堂√最新版中文在线| 国産精品久久久久久久| 亚洲午夜精品久久久久久浪潮| 日日碰狠狠添天天爽超碰97久久| 亚洲精品无码成人片| 国产H视频在线观看| 少妇A片出轨人妻偷人视频| 麻豆高清免费国产一区| 女人18毛片a级毛片免费视频| 成人做受视频试看60秒| 人人妻人人添人人爽欧美一区| 免费AV在线| 欧洲-级毛片内射八十老太婆| 亚洲精品~无码抽插| 亚洲乱色伦图片区小说| 中文乱码字慕人妻熟女人妻| 日韩AV爽爽爽久久久久久 | 亚洲AV午夜精品一区二区三区| 老中医吮她的花蒂和奶水视频播放| 日韩精品一区二区三区在线观看| 无码人妻久久久一区二区三区 | 亚洲国产精品尤物YW在线| 高潮A片揉搓乳尖乱颤视频| 国产乡下三级全黄三级bd| CHINESEMATURE老熟妇 | 无码精品国产一区二区三区免费| 天天干天天日| 久久香蕉国产线熟妇人妻| 欧美成人精品A片免费区网站| 久久精品99久久久久久久久|