Raspailynes, Novel Long‐Chain Acetylenic Enol Ethers of Glycerol from the Marine Sponges Raspailia pumila and Raspailia ramosa

• Published in: Helvetica Chimica Acta
• Main Authors: Guella, Graziano, Mancini, Ines, Pietra, Francesco
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1987
• Subjects: North East Atlantic
• Online Access: http://dx.doi.org/10.1002/hlca.19870700417; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhlca.19870700417; https://onlinelibrary.wiley.com/doi/pdf/10.1002/hlca.19870700417

Abstract The sponges Raspailia pumila and ramosa (Demospongiae, Tetractinomorpha, Axinellida) from the North‐East Atlantic are shown to contain a series of novel long‐chain enol ethers of glycerol where the enol ether CC bond is conjugated, in sequence, to both an acetylenic and an olefinic bond. Polar extracts give raspailynes hydroxylated at their (1 Z 5 Z )‐1,5‐alkadien‐3‐ynyl chain, like raspailyne Al ( = (+)‐( S )‐3‐[((1 Z ,5 Z )‐16‐hydroxy‐hexadeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; (+ 2 ) and isoraspailyne A ( = (+)‐3‐[((1 Z ,5 Z )‐17‐hydroxyocta‐deca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐[propanediol; (+)‐ 3 ). Less polar extracts give 3 different types of raspailynes not hydroxylated at the chain. Raspailynes of the first type have either the (1 Z ,5 Z )‐configuration in a linear chain such as raspailyne B2 (( = (−)‐( s )‐3‐[((1 Z ,5 Z )‐trideca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; (−)‐ 4 ), raspailyne Bl ( = (−)‐3‐[((1 Z ,5 Z )‐tetradeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol;(−)‐ 5 ), and raspailyne B ( = 3‐[((1 Z ,5 Z )‐pentadeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 6 ) or the (1 Z ,5 Z )‐pentadeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 6 )or the (1 Z ,5 Z )‐configuration in a chain ending with an isopropyl group, like isoraspailyne Bl ( = 3‐[((1 Z ,5 Z )‐12‐methyltrideca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 7 ) and isoraspailyne B ( = 3‐[((1 Z ,5 Z )‐13‐methyltetradeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 8 ). Raspailynes of the second type have the (1 Z ,5 E )‐configuration, like isoraspailyne Bla ( =3‐[((1 Z ,5 E )‐tetradeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 9 ) and isoraspailyne Ba ( = 3‐[((1 Z ,5 E )‐13‐methyltetradeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2‐propanediol; 10 ). Raspailynes of the third type have the (1 E ,5 Z )‐configuration, like isoraspailyne Blb ( = 3‐[((1 E ,5 Z )‐tetradeca‐1,5‐dien‐3‐ynyl)oxy]‐1,2,‐propanediol; 11 ). The ( S )‐configuration for (+)‐ 1 ,((+)‐ 2 , and (−)‐ 4 is derived from chemical correlations.