A Novel, One-Pot Ring Expansion of Cyclobutanones. Syntheses of Carbovir and Aristeromycin
作者:Brian Brown、Louis S. Hegedus
DOI:10.1021/jo9919759
日期:2000.3.1
A novel, one-pot ring-expansion procedure was developed using Me3S(O)I, NaH, and Sc(OTf)3. The scope and limitations were briefly examined, and a tentative mechanism was proposed. Application of the methodology to known cyclobutanone 1 provided the corresponding cyclopentanone, which was successfully advanced to (+)-carbovir and (+)-aristeromycin.
Effect of β-Substituents on the Regioselectivity of the Diazomethane Ring Expansion of α-Methyl-α-methoxycyclobutanones to Cyclopentanones
作者:Lisa M. Reeder、Louis S. Hegedus
DOI:10.1021/jo990226o
日期:1999.4.1
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.