Regioselective Tandem Dimethylsulfonium Methylide Addition−Eliminative Olefination of Diendioates:  A Novel Route to 1,3-Butadien-2-ylmalonates

Abstract

The appropriate choice of dimethylsulfonium methylide generation conditions enables the highly regioselective tandem ylide addition-eliminative olefination to 1,3-dienedioates providing 1,3-butadien-2-ylmalonates, a novel class of 2-substituted 1,3-dienes suitable for quick assembly of precursors for type 2 intramolecular Diels-Alder reactions.

First Synthesis of 9,10‐Dimethoxy‐2‐methyl‐1,4‐anthraquinone: A Naturally Occurring Unusual Anthraquinone

“…However, both attempts failed to give any tractable product corresponding to the methylation. For the direct formation of 3 , we first attempted the recently reported Ghosh protocol involving a sulfur ylide 25. Treatment of 25 with the ylide from trimethylsulfonium iodide followed by workup of the mixture provided a mixture of products.…”

An Organocatalyzed Asymmetric Michael Addition of Cyclic Ketones to 1,3‐Diene‐1,1‐dicarboxylates

“…Elemental analyses (C, H, N) were carried out by Elementar, varioMICRO CHNS instrument. Diene dicarboxylates 1a – 1h were prepared by following a reported general procedure 13b,13c. Organocatalysts 2a ,5g 2b ,5n 2c ,5j and 2d – 2f 5o were prepared by following the literature procedures.…”

Reactions of Styrylmalonates with Aromatic Aldehydes: Detailed Synthetic and Mechanistic Studies

“…It should be noted that styrylmalonates themselves have been already been known for a long time in organic chemistry. However, their further use is almost unknown, and the number of styrylmalonates obtained is very limited …”