(2S,3R,4S,5R,6S)-6-Benzyloxymethyl-4-(methoxymethyloxy)-9-oxo-8-oxa-1-azabicyclo[4.3.0]nonane-2,3,5-triyl triacetate.

The relative configuration of the title compound, C(23)H(29)NO(11), prepared in a synthetic study on the natural product sphingofungin E, has been determined. The six-membered ring adopts a chair form and the five substituents are all axial.

Effectiveness of preventive surgery for asymptomatic unruptured intracranial aneurysms.

Recently in Japan, physicians used MRI angiography (MRA) for the detection of asymptomatic intracranial diseases. Asymptomatic unruptured intracranial aneurysms (UIAs) are one of the most common abnormalities; usually the patients are advised to undergo preventive surgery. We evaluated the effectiveness of preventive surgery for asymptomatic UIAs, using published data in the literature with decision analysis on a Markov model. The baseline analysis showed that preventive surgery is superior to follow-up in a wide range of patient ages, but only by small QALY margin. Sensitivity analyses showed that the rate of rupture and the clinical outcome of surgery will influence the choice.