Diastereodivergent Construction of Octahydrophenanthridinone and Octahydrophenanthridine Cores.

Diastereodivergent synthesis of octahydrophenanthridinone and octahydrophenanthridine skeletons, structural motifs often found in biologically active natural products, is described. We previously reported a total synthesis of a pancratistatin analog using novel octahydrophenanthridinone construction. In this study, we examined the generality of our method and its extension to octahydrophenanthridine formation.

Portal-Vein Compression Caused by Double-Pigtail Plastic Biliary Stent.

Introduction: Reports of pseudoaneurysms associated with biliary self-expandable metallic stent (SEMS) placement have been increasing. Recently, cases of hepatic pseudoaneurysm rupture caused by double pigtail plastic stents (DPS) have also been reported. The symptoms of pseudoaneurysms are often non-specific, and many cases are diagnosed only after rupture.

Safety and efficacy of underwater EMR for 10- to 20-mm colorectal serrated lesions (SEA CLEAR study).

Background And Aims: Colorectal serrated lesions (SLs) are precursors of colorectal carcinoma via the serrated neoplasia pathway. However, the success rate of endoscopic resection of large SLs is low. Therefore, this study aimed to determine the safety and efficacy of underwater EMR (UEMR) for SLs sized 10 to 20 mm.

Total synthesis of 1,4a-di--pancratistatin, exemplifying a stereodivergent approach to pancratistatin isomers.

The total synthesis of 1,4a-di--pancratistatin, a novel stereoisomer of the anti-tumor alkaloid pancratistatin, was achieved in 14 steps starting from D-mannitol. The construction of the pancratistatin skeleton involved conjugate addition of organocuprate to a nitrosoolefin, which was generated from inosose oxime. This was followed by stereoselective reduction of the oxime to an amine and site-selective formylation.