Pleraplysilla spinifera

A total synthesis of ( )-dihydrospiniferin-l (149), an unstable furanosesquiterpene from the Mediterranean sponge Pleraplysilla spinifera, has been reported. It is of interest because (149) is the first reported natural product incorporating the novel l,6-methano[10]annulene carbon framework (80JA4274). The key step in the synthesis is the condensation of the aldehyde (150) with methoxymethylenetriphenylphosphorane in toluene to give the bis-enol ether (151). Treatment of (151) with aqueous hydrochloric acid in diethyl ether affords the furan (149). 

Fontana, A., Gimenez, F., Marin, A., Mollo, E., and Cimino, G., Transfer of secondary metabolites from the sponges Dysideafragilis and Pleraplysilla spinifera to the mantle dermal formations (MDF s) of the nudibranch Hypserlodoris webbi, Experientia, 50, 510, 1994. 

SPECTRAL data UV, PMR, Mass Spec organism Pleraplysilla spinifera (Porifera) reference 98... 

Cimino, G., De Stefano, S., Minale, L., and Trivellone, E. (1972b) New sesquiterpenes from the marine sponge Pleraplysilla spinifera. Tetrahedron, 28, 4761-4767. 

Knight, D.W. and Rustidge, D,C, (1981) General routes to 4-methyl-2-substituted furans a synthesis of pleraplysillin-2 from metabolite of sponge Pleraplysilla spinifera. J. Chem. Soc. Perkin Trans. I, 679-683. 

Glossodoris valenciennesi Longifolin Pleraplysilla spinifera Cimino eto/., 1975c, 1978, 1982... 

Hypselodoris daniellae Spiniferin-2 hemorrhages Pleraplysilla spinifera Schulte and Scheuer, 1982... 

The chemical study of Pleraplysilla spinifera led to the isolation of six new furanosesquiterpenes. Two different samples identified as the same species (probably different varieties), both collected in the Bay of Naples, were analyzed and found to possess different sesquiterpene constituents. Chart 4 list their structures. 

The second sample of Pleraplysilla spinifera contains longifolin (39), previously found in a terrestrial plant, Actinodaphne longifolia, by Hayashi et al. 113), and two more cyclic furanosesquiterpenes (57). On the basis of a careful n.m.r. examination, alternative structures (40a) and (40b) and (41a) and (41b), respectively, containing carbon skeletons of a new sesquiterpenoid have been proposed for the two polycyclic components which were designated spiniferin-2 and -1. 

---