Total Synthesis and Stereochemical Assignment of Callyspongiolide

Total synthesis of four callyspongiolide stereoisomers led to unambiguous assignment of relative and absolute stereochemistry of the natural product. Key features of the convergent, fully stereocontrolled route include the use of Krische allylation, Kiyooka Aldol reaction, Kociénski–Julia olefination, Still–Gennari olefination, Yamaguchi macrocyclization, and Sonogashira coupling reaction. Biological evaluation of the synthesized compounds against an array of cancer cells revealed that the stereochemistry of the macrolactone core played an important role

Regio- and Stereospecific Construction of 3a-(1<i>H</i>‑Indol-3-yl)pyrrolidinoindolines and Application to the Formal Syntheses of Gliocladins B and C

A one-pot regio- and stereospecific strategy for the construction of 3a-(3-indolyl)-hexahydropyrrolo­[2,3-<i>b</i>]­indoles based on the condensation of an indole and an in situ generated cyclopropylazetoindoline has been developed. This unified strategy works with a variety of substituted indoles to produce 3a-(3-indolyl)­hexahydropyrrolo­[2,3-<i>b</i>]­indole products in high yields. The utility of this transformation was highlighted in the formal total syntheses of gliocladins B and C

Studies toward the Synthesis of Iriomoteolide-2a: Construction of the C(6)–C(28) Fragment

The synthesis of an appropriately functionalized advanced C(6–28) fragment (<b>3</b>) of the marine macrolide iriomoteolide-2a (<b>1</b>) has been achieved in a highly efficient manner. The C(6)–C(18) fragment of <b>1</b> is prepared via a radical cyclization of a vinyl ether intermediate and palladium-promoted hydrostannylation/iodination. Paterson aldol reaction and Peterson olefination are used to construct the C(19)–C(28) fragment. The union of the C(6)–C(18) and C(19)–C(28) fragments is accomplished via a Suzuki–Miyaura coupling reaction