Chiral Pool Meets Chiral Catalysis: Eight-Step Convergent Total Synthesis of Anticancer Natural Lipid Mycalol.

An exemplary blend of chiral pool with chiral catalysis is exhibited in an eight-step (longest) convergent asymmetric total synthesis of mycalol, which is a promising anticancer natural lipid from a marine source. The polyhydroxy lipid is constructed by using four blocks, and two of which are derived from the chiral pool (d-mannitol and d-gluconolactone) and the other two by chiral catalysis (Sharpless epoxidation and Keck allylation). Alkylation and metathesis were used to knit the blocks in an excellent display of a modular convergent eight-step synthesis.

Recent advances in the syntheses of guaianolides.

Sesquiterpene lactones, especially guaianolides representing a bigger class of natural products, have served as appealing candidates for total synthesis due to their varied bio- and pharmaceutical activities. This tutorial review delineates the creative efforts of many researchers in the total syntheses of different complex guaianolides recently published in the literature. Many of the syntheses display meticulous interplay between new methods and the ingenuity of strategies achieved through well-planned routes.

TBAI-Catalyzed Regioselective Hydroxyperoxidation of 1-Aryl/Alkyl-1,3-dienes.

An efficient, mild, and economical approach for regioselective synthesis of 4-aryl/alkyl-1-peroxy-but-3-en-2-ols from 1-substituted-1,3-butadienes using hydroperoxides and catalyzed by TBAI has been developed. This method can be executed in a simple operation with no dry conditions required and having tolerance to a wide range of substrates to access corresponding hydroxyperoxidates in good yields. Thus, an excellent regioselective orthogonal dioxygenation in a diene system has been achieved.

Palladium-Catalyzed Regioselective Intermolecular Hydroalkoxylation of 1-Arylbutadienes.

An efficient method for the synthesis of ()-(3-alkoxybut-1-enyl)benzenes by Pd-catalyzed regioselective intermolecular hydroalkoxylation of 1-arylbutadienes has been developed. This method can be executed in a simple operation with no dry reaction conditions required and having tolerance to a wide range of substrates. Chloromethyl methyl ether (MOMCl) as an additive was found to be essential for the success of the reaction.