特異な構造や生物活性を有するテルペノイドの不斉全合成

抄録

Asymmetric total synthesis of sarcophytols A and T, hippospongic acid A, octalactin A and glabrescol has been summarized in this review. Baker's yeast reduction is used as a chilarity induction method. Both enantiomers of sarcophytols A and T, an inhibitor of tumor promoter, were synthesized using stereospecific [2, 3] -Wittig rearrangement as the key step. The structure of hippospongic acid A exhibiting inhibitory activity for gastrulation of starfish embryos was revised by asymmetric synthesis and its absolute configuration was determined. A key compound for the synthesis of cytotoxic octalactin A was prepared efficiently starting from (-) -citronellol. A compound having the structure proposed for glabrescol, a meso-type triterpene containing five continuously linked tetrahydrofuran rings, and one of its diastereomer were synthesized enantioselectively. Comparison of NMR spectra of all of thus synthesized authentic diastereomers revealed that there was some mistakes in elucidation of the stereochemistry of the natural product.