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.
Synthesis of cyclobutanones by the photolytic reaction of chromium carbene complexes with olefins: inter- and intramolecular reactions
作者:Bjorn C. Soderberg、Louis S. Hegedus、Miguel A. Sierra
DOI:10.1021/ja00167a038
日期:1990.5
Formation of cyclobutanones by the photolytic reaction of chromium carbene complex (CO)5Cr:C(OMe)Me with electron-rich olefins
作者:Miguel A. Sierra、Louis S. Hegedus
DOI:10.1021/ja00188a076
日期:1989.3
of useful organic synthetic methodology based on the photolyticreactions of chromium Fischer carbenecomplexes, particularly in regards to the development of new /beta/-lactam syntheses. In the course of these studies it became evident that photolysis of chromium-carbene complexes resulted in the reversible production of chromium-ketene complexes, by a photochemically driven CO insertion into the chromium-carbene
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.