Stereoselective Total Synthesis of (+)-Sapinofuranone B

Decarboxylative Alkynylation

The development of a new decarboxylative cross-coupling method that affords terminal and substituted alkynes from various carboxylic acids is described using both nickel- and iron-based catalysts. The use of N-hydroxytetrachlorophthalimide (TCNHPI) esters is crucial to the success of the transformation, and the reaction is amenable to in situ carboxylic acid activation. Additionally, an inexpensive, commercially available alkyne source is employed in this formal homologation process that serves as a surrogate for other well-established alkyne syntheses. The reaction is operationally simple and broad in scope while providing succinct and scalable avenues to previously reported synthetic intermediates.

Synthesis and biological evaluation of sapinofuranones A,B and 1,2,3-triazole-sapinofuranone hybrids as cytotoxic agents

The total synthesis of sapinofuranones A,B and ent-sapinofuranones A,B and L-factor and a series of novel 1,2,3-triazole-sapinofuranone hybrids is described and their cytotoxicity against four human cancer cell lines (A549, MDA-MB-231, DU145 and HepG2) was evaluated.

Synthesis and determination of absolute configuration of α-pyrones isolated from Penicillium corylophilum

The first total synthesis of (S)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one, 4-hydroxy-3-methyl-6-((2S,4R)-2,4,11-trihydroxyundecyl)-2H-pyran-2-one, and its unnatural 2R,4R-isomer starting from commercially available 1,8-octanediol is described. The synthesis led to the revision of the proposed structural assignment of the natural product as (R)-6-(2,9-dihydroxynonyl)-4-hydroxy-3-methyl-2H-pyran-2-one. The key steps include chiral auxiliary mediated asymmetric acetate aldol reaction, dianion addition, and base mediated cyclization to form an α-pyrone ring.