Lithium-Tellurium Exchange: A New Entry to Organolithium Compounds

✍ Scribed by Tomoki Hiiro; Dr. Nobuaki Kambe; Dr. Akiya Ogawa; Dr. Noritaka Miyoshi; Dr. Shinji Murai; Prof. Dr. Noboru Sonoda

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 259 KB
• Volume: 26
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198711871

✦ Synopsis

NMR spectra (in [D],DMF) of natural D and synthetic 4 were essentially identical, particularly in the region representing olefinic protons (6 = 5.6-6.8). This, in turn, proves that the the component D is pure all-trans-fecapentaene-14 (4).

We have also established that the CI mass spectra of the natural and the synthetic compounds are identical. These spectra, however, show very little fragmentation, and thus are not sufficiently informative.

These investigations enable us for the first time to assign the complete structural formulas to two naturally occurring fecapentaenes. The geometry of the CC double bonds may play a role in the degree of mutagenicity exhibited by both types of fecapentaene~.''.~~ Interestingly, the two identified components, all-trans-fecapentaene-12 (3)[91 and alltrans-fecapentaene-I4 (4)['] belong to the most potent mutagens so far known. Their occurrence in human feces and their accessibility by chemical synthesis raise hopes that they might serve to answer the question whether the fecapentanes are carcinogens.