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发帖数: 1050 | 1 在有AlCl3的甲苯溶剂，为什么乙酯比甲酯容易脱保护?
谢谢 | w**q
发帖数: 43 | 2 Just a thought.
For ester alone, s-cis form is favored(anomeric, A1,2 and dipole).
After addn of AlCl3, for Me, the s-trans...AlCl3 could be stable since Me is
small. But for Et, both s-cis...AlCl3 and s-trans...AlCl3 are unstable
complex due to steric effect. s-cis...AlCl3 is ready for IM cleavage of Et. |
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