Synthetic Utilization of 2H-Heptafluoropropane: Ionic 1,4-Addition to Electron-Deficient Carbon-Carbon Unsaturated Bonds.

We have found a novel method for introducing heptafluoro-2-propyl CF(CF3)2 groups into carbon-carbon unsaturated bonds via a nucleophilic reaction using 2H-heptafluoropropane as the source of CF(CF3)2 groups. The reaction involves the nucleophilic addition of a heptafluoro-2-propyl anion, generated by treating 2H-heptafluoropropane with a fluoride ion, to various electron-deficient unsaturated compounds. This allows the easy synthesis of various aliphatic compounds containing heptafluoro-2-propyl groups.

Asymmetric Total Synthesis of (-)-Astakolactin and Confirmation of Its Stereostructure.

The originally proposed structure of astakolactin was revised, and an asymmetric total synthesis of the newly proposed structure was achieved. The key transformations in the synthesis were a Johnson-Claisen rearrangement, an asymmetric Mukaiyama aldol reaction, and a Mitsunobu-type cyclodehydration. The spectroscopic data and specific rotation of the compound obtained matched well with those reported for naturally occurring astakolactin.

Total synthesis of the proposed structure of astakolactin.

The first total synthesis of the proposed structure of astakolactin, a sesterterpene metabolite isolated from the marine sponge Cacospongia scalaris, has been achieved, mainly featuring Johnson-Claisen rearrangement, asymmetric Mukaiyama aldol reaction and MNBA-mediated lactonization.