Total synthesis of (+/-)-hapalindole Q.

[reaction: see text] The total synthesis of the antibacterial and antimycotic alkaloid hapalindole Q has been achieved in eight steps and 12.4% overall yield. The key step involves a regio- and diastereoselective Diels-Alder reaction to afford a bicyclo[2.2.2]oct-2-ene. This cycloadduct was subsequently dihydroxylated, cleaved, and converted to the natural product.

Highly selective Diels-Alder reactions of dienophiles with 1, 3-cyclohexadiene mediated by Yb(OTf)(3).2H(2)O and ultrahigh pressures.

[reaction: see text] Ultrahigh pressures and catalytic Yb(OTf)(3).2H(2)O were found to mediate Diels-Alder reactions of various electron-deficient dienophiles with 1,3-cyclohexadiene to produce endo-bicyclo[2.2. 2]oct-2-enes in moderate to excellent yield and selectivity. The proposed total synthesis of hapalindole Q based on bicyclo[2.2. 2]oct-2-ene construction by Diels-Alder reaction and subsequent olefin cleavage is outlined. Preliminary results demonstrating the viability of this strategy are presented.