The absolute configuration of cycloeudesmol from the red alga Laurencia nipponica Yamada

✍ Scribed by Teruaki Suzuki; Akio Furusaki; Hajime Kikuchi; Etsuro Kurosawa; Chuji Katayama

• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 229 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)81922-5

✦ Synopsis

The absolute configuration of cycloeudesmol, isolated from the red alga Lauren&a nipponica Yamada and Chondria oppositiclada Dawson, is determined by the crystallographic study. In our previous report'), the structure of isocycloeudesmol, C15HZ60, isolated from L. nipponica Yamada, has been proposed as the formula 1 by the spectral and chemical evidences. On the other hand, cycloeudesmol, C15HZ60, was isolated from the red alga C. oppositiclada Dawson by Fenical and Sims 31 and its structure was proposed as shown in the formula 2 and the syntheses of four possible stereoisomers of 2 have been attempted in three laboratories 4) . -Recently, the total syntheses of the stereoisomers of 2 have been completed and they were found to be different from the natural cycloeudesmol and it was concluded that the structure (2) of cycloeudesmol, proposed by Fenical and Sims, should be revised4b). Meanwhile, the cautious comparison of IR and lH NMR spectra and the optical rotation 5) came to the conclusion that isocyclo-1