Paper
Regioselective Synthesis Mechanism and Crystal Structure of 2′,4″-O-Bis(trimethylsilyl)-6-O-methylerythromycin A 9-O-(1-methoxycyclohexyl) oxime
Published 2007 · Liang Jian
Chemical Journal of Chinese Universities-chinese
0
Citations
0
Influential Citations
Abstract
2′,4″-O-Bis(trimethylsilyl) 6-O-methylerythromycin A 9-O-(1-methoxycyclohexyl) oxime was regioselectively synthesized and characterized and its crystal structure was determined by the single crystal X-ray structure analysis. The crystal belonged to tetragonal system with I4 space group and a=b=2.9720(4) nm, c=1.4939(3) nm, V=13.195(4) nm3, Z=8, R=0.0587, wR=0.1263, S=1.004 for 11526 unique reflections. The crystal structure shows that the attack of methylation reagents was blocked by 9-oxime ether as result, a hydrogen bond formed between 11-OH and nitrogen of 9-oxime, and the attack of methylation reagents was blocked by 9-oxime ether, whereas the orientation of 6-OCH3 was located in the cave surrounded by several rings so that 6-OH was unique one to be exposed to methylation reagents. However, the congestion around 11-OH was loosened, which resulted from the orientation of protective group so that much 6,11-O-dimethyl product was yielded. Additionally, the crystal structure of 2′,4″-O-bis(trimethylsilyl) erythromycin A 9-O-(1-methoxy-1-methylethyl) oxime was first disclosed as a comparison.
The crystal structure of 2′,4′′-O-Bis(trimethylsilyl)-6-O-methylerythromycin A (9-O-(1-methoxycyclohexyl) oxime reveals a unique regioselective synthesis mechanism and a new crystal
Sign up to use Study Snapshot
Consensus is limited without an account. Create an account or sign in to get more searches and use the Study Snapshot.
Full text analysis coming soon...