Visible-Light-Mediated Oxidative Debenzylation Enables the Use of Benzyl Ethers as Temporary Protecting Groups.

The cleavage of benzyl ethers by catalytic hydrogenolysis or Birch reduction suffers from poor functional group compatibility and limits their use as a protecting group. The visible-light-mediated debenzylation disclosed here renders benzyl ethers temporary protective groups, enabling new orthogonal protection strategies. Using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a stoichiometric or catalytic photooxidant, benzyl ethers can be cleaved in the presence of azides, alkenes, and alkynes.

High stability of the Ilizarov ringfixator in a metacarpal fracture of an Arabian foal.

In a case of I degree open multifragmentary metacarpal fracture of a 4-week-old Arabian foal, an osteosynthesis with the Ilizarov ringfixator was performed. Immediate full weight-bearing (100 kg) was possible, demonstrating the high stability of the Ilizarov ringsystem. After 12 weeks, sufficient bony union was achieved, and the fixator could be removed.