Posterior epidural disc herniation at L3-L4 mimicking a spinal tumor: a case report.

Posterior epidural disc migration is a rare event. Many differential diagnoses are possible in the posterior epidural space other than disc disease. This is a case report of L3-L4 posterior epidural disc herniation that was misdiagnosed as a tumor depending on the preoperative magnetic resonance imaging study with a peripheral ring enhancement around the mass lesion after IV gadolinium. Decompressive L4 laminectomy was performed and a free disc fragment was observed beneath the lamina. There wasneither dural tearnor attachment to it. The patient was free of pain postoperatively. After 3 months, the patient applied to the outpatient clinic for a regular control T he patient was neurologically intact and free of pain. Diagnosis of posterior migrated disc fragment with subtle clinical findings, even though the free fragment has to pass through many anatomical barriers including the nevre roots, is a clinical challenge. Many differential diagnoses should be kept in mind. MRI findings (especially with contrast material use) are useful which should be imprinted with clinical knowledge.

Detection and reactivity of Pd((C8H14)PCH2 CH2 P(C8H14))(CHPhCH2Ph)(H) as determined by parahydrogen-enhanced NMR spectroscopy.

Pd(bcope)(OTf)2 (where bcope is (C8H14)PCH2CH2P(C8H14)) is shown to react with an alkyne in the presence of parahydrogen to form alkyl hydrides, such as Pd(bcope)(CHPhCH2Ph)(H), that are detectable by NMR spectroscopy because the proton resonances of the alkyl arm appear with strongly enhanced signal strengths.

Regiochemistry in the Pauson-Khand reaction: has a trans effect been overlooked?

Alkyne-dicobalt hexacarbonyl complexes have been studied by DFT to examine whether electronic differences in the acetylenic substituents could play a role in determining the regiochemical outcome in the Pauson-Khand reaction. It appears that in some instances the regiochemistry is, in fact, governed exclusively by the electronic nature of the acetylenic substituents through the discriminant loss of a carbon monoxide ligand.