Studies directed toward synthesis of taepeenin D: construction of the C4 stereogenic center and the CD benzofuran rings. Issue 24 (15th June 2016)

• Record Type: Journal Article
• Authors: Nakazawa, Yuichiro; Nagatomo, Meri; Oikawa, Tsuyoshi; Oikawa, Masato; Ishikawa, Yuichi
• Is Part Of: Tetrahedron letters. Volume 57:Issue 24(2016)
• Page Start: 2628
• Page End: 2630
• Publication Date: 2016-06-15
• Subjects: Hedgehog signaling pathway -- Taepeenin D -- Cyclic ether formation -- Regioselective C–C bond formation -- Benzofuran; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2016.05.005
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Taepeenin D is a meroterpenoid isolated from roots and stems of Caesalpinia crista . This compound exhibited inhibitory activity of Hedgehog signaling pathway. Construction of the quaternary carbon stereogenic center at C4 was accomplished. The CD benzofuran rings were selectively constructed in a stepwise manner. The D ring was manipulated in 2 steps shorter than that in the previous study. Abstract: Taepeenin D is a meroterpenoid isolated from roots and stems of Caesalpinia crista, showing inhibitory activity of Hedgehog signaling pathway. Herein we report selective and short-step construction of two fragments of taepeenin D. First, we demonstrated alkoxy radical-mediated selective functionalization at C19 methyl group for construction of the C4 quaternary carbon stereogenic center. Second, the CD benzofuran rings were constructed in 6 short steps from decalone. The synthesis described herein is not only applicable to total synthesis, but also used for study of the structure–activity relationships of taepeenin D.