189. Sarcodictyin A and Sarcodictyin B, Novel Diterpenoidic Alcohols Esterified by (E)-N(1)-Methylurocanic Acid. Isolation from the Mediterranean Stolonifer Sarcodictyon roseum

Article abstract of DOI:10.1002/hlca.19870700807

The Mediterranean stolonifer Sarcodictyon roseum (=Rolandia rosea) ( Cnidaria, Anthozoa, Alcyonaria, Stolonifera, Clavulariidae) is shown to contain two novel diterpenoidic alcohols esterified by (E)-N(1)-methylurocanic acid (= (E)-3-(1-methyl-1H-imidazol-4-yl)acrylic acid).They are sarcodictyin A (= (-)-(4R,4aR,7R,10S,11S,12aR,1Z,5E,8Z)-7,10-epoxy-3,4,4a,7,10,11,12,12a-octahydro-7-hydroxy-6-(methoxycarbonyl)-1,10-dimethyl-4-(1-methylethyl)benzocyclodecen-11-yl (E)-3-(1-methyl-1H-imidazol-4-yl)acrylate; (-)-1) and sarcodictyin B (the 6-(ethoxycarbonyl analogue; (-)-2).The assignment of the structures is based on 1D- and 2D-NMR data, as well as on mainly chemical transformations of (-)-1, such as transesterification with MeONa/MeOH giving methyl (E)-N(1)-methylurocanate (3) and the free alcohol (+)-4 and reduction with LiAlH4 followed by benzoylation giving dibenzoate 7.Absolute configurations are based on Horeau's method of esterification of (+)-4.