The ring expansion of 22 differently beta-substituted alpha-methyl-alpha-methoxycyclobutanones by diazomethane was studied. Migration of the less-substituted alpha-carbon was favored with the single exception of a very sterically hindered beta-benzyloxy beta-substituent.
                                    研究了
重氮甲烷对22种不同的β-取代的α-甲基-α-甲氧基
环丁酮的扩环作用。除了非常受空间阻碍的β-苄氧基β-取代基以外,较少取代的α-碳的迁移是有利的。