A highly efficient stereoselective synthesis of (Z)- and (E)-allyl iodides from Baylis–Hillman adducts

Bioinspired Total Synthesis of (+)-Euphorikanin A

We have achieved a bioinspired total synthesis of (+)-euphorikanin A, which possesses an intriguing and complex 5/6/7/3-fused tetracyclic skeleton bearing a bridged [3.2.1]-γ-lactone moiety. Key transformations include stereoselective alkylation and aldol condensation to install the main stereocenters, an intramolecular nucleophile-catalyzed aldol lactonization of carboxylic acid-ketone to assemble the five-membered ring, a McMurry coupling to construct the seven-membered ring, and a biomimetic benzilic acid type rearrangement to form the bridged [3.2.1]-γ-lactone moiety.

A Mild and Efficient Stereoselective Synthesis of (Z)- and (E)-Allyl Sulfides and Potent Antifungal Agent, (Z)-3-(4-Methoxybenzylidene)thiochroman-4-one from Morita-Baylis-Hillman Acetates

A facile stereoselective synthesis of (Z)- and (E)-allyl sulfides has been accomplished from Morita-Baylis-Hillman acetates in one-pot by treatment with benzene thiol in the presence of catalytic amounts of 15% aqueous NaOH and TBAI in DMSO at room temperature. The method has been applied for the synthesis of (Z)-3-(4-methoxybenzylidene)thiochroman-4-one, a potent antifungal compound.

Allyl and benzyl iodides by the anomalous action of iodotrimethylsilane

Iodotrimethylsilane (TMSI), routinely used for the dealkylation of ethers and esters, has been found to efficiently convert allyl and benzyl phosphotriesters into the corresponding iodides under mild, Brønsted-neutral conditions. In contrast, alkyl and aryl phosphotriesters were dealkylated to the corresponding phosphates under identical conditions.

A convenient and stereoselective synthesis of (Z)-allyl selenides via Sm/TMSCl system-promoted coupling of Baylis-Hillman adducts with diselenides

A simple and convenient procedure for stereoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCl system to form selenide anions, which then undergo S(N)2' substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides.

Synthetic Applications of Baylis-Hillman Chemistry: An Efficient and Solely Stereoselective Synthesis of (E)-.ALPHA.-Methylcinnamic Acids and Potent Hypolipidemic Agent LK-903 from Unmodified Baylis-Hillman Adducts

An efficient and solely stereoselective synthesis of (E)-alpha-methylcinnamic acids has been accomplished in single pot by reduction of the unmodified Baylis-Hillman adducts, methyl-3-hydroxy-3-aryl-2-methylenepropanoates with I(2)/NaBH(4) reagent system at room temperature followed by hydrolysis. The efficacy of this method has been proved in the total synthesis of 1-[p-(myristyloxy)-alpha-methylcinnamoyl]glycerol, LK-903, a highly active hypolipidemic agent.