Highly diastereoselective dioxetane formation in the photooxygenation of enecarbamates with an oxazolidinone chiral auxiliary: steric control in the [2 + 2] cycloaddition of singlet oxygen through conformational alignment.
The photooxygenation of oxazolidinone-substituted enecarbamates leads to diastereomerically pure dioxetanes. The high diastereoselectivity is rationalized in terms of effective pi-facial control achieved by shielding one side of the double bond with the chiral auxiliary. The absolute configuration of the dioxetanes is assigned by derivatization to diols.
Institut für Organische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Waldemar
W
Adam
Sara G
SG
Bosio
Nicholas J
NJ
Turro