Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF<sub>3</sub>·Et<sub>2</sub>O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products
achieved by controlling the loading of BF3·Et2O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.
In Situ Generation and Intramolecular Schmidt Reaction of Keto Azides in a Microwave-Assisted Flow Format
作者:Thomas O. Painter、Paul D. Thornton、Mario Orestano、Conrad Santini、Michael G. Organ、Jeffrey Aubé
DOI:10.1002/chem.201100768
日期:2011.8.22
Go with the flow! A method for conversion of keto halides to lactams by means of sequential azidation and intramolecularSchmidtreaction in a combined flowformat is described (see scheme; MWI=microwave irradiation, TFA=trifluoroacetic acid).
Organocatalytic, Chemoselective, and Stereospecific House–Meinwald Rearrangement of Trisubstituted Epoxides
作者:Peter R. Schreiner、Friedemann Dressler、Victoria Öhler、Christopher Topp
DOI:10.1055/a-2216-4710
日期:——
We present a novel method for the chemoselective House–Meinwald rearrangement of trisubstituted epoxides under mild conditions with the use of simple perfluorinated disulfonimides as Brønsted acid catalysts. We isolated the α-quaternary aldehyde products in yields of 27–97% using catalyst loadings as low as 0.5 mol% on a scale of 1 mmol. In addition, we show the stereospecific rearrangement using an