Publications by authors named "R J Wiechert"

The carbon skeleton of any organic molecule serves as the foundation for its three-dimensional structure, playing a pivotal role in determining its physical and biological properties. As such, taxane diterpenes are one of the most well-known natural product families, primarily owing to the success of their most prominent compound, paclitaxel, an effective anticancer therapeutic for more than 25 years. In contrast to classical taxanes, the bioactivity of cyclotaxanes (also referred to as complex taxanes) remains significantly underexplored.

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A short synthesis of the ergot alkaloid lysergene and a formal total synthesis of lysergic acid diethylamide (LSD) under the avoidance of palladium and including two nickel-catalyzed steps instead have been developed. A key intermediate of this approach has already been reported by Hendrickson et al. in 2004 (Hendrickson, J.

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Background: Diamond-Blackfan anemia is a rare form of congenital red-cell aplasia. Approximately 90% of the patients are diagnosed by 1 year of age. This report presents two pregnancies with good outcomes in a patient over a period of 1.

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A partial synthesis of the title compound, 4'-(dimethylamino)-17 beta-hydroxy-17 alpha-(1-propynyl)benzo[12,12a]-11 alpha,18-cyclo-12a,12b- dihomo-13 alpha-estr-4-en-3-one 1, is reported. The key step in this synthesis represents an intramolecular alkenylaryl radical cyclization. Treatment of 18-[bromo-5-(dimethylamino)phenyl]gona-5,9(11)-diene-3,17-dione-3, 17- bis[cyclic 1,2-ethanediyl acetal] 5 with tributyl tin hydride and a radical initiator introduces the desired 11 beta,18-bridge.

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An efficient approach to 17-chloro-16(17) unsaturated D-homo antiprogestins is described. The key steps of the synthesis are a ring-expansion via dichlorocarbene addition to a 17-silyl enol ether and a palladium catalyzed coupling of an 11 beta-(4-aryltriflate) with tributyl(1-ethoxyethenyl)stannane or diethyl(3-pyridinyl)-borane. The new progesterone antagonists were tested for their biological activities and compared to those of known antiprogestins.

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