From Laurencia nipponica

During this investigation the authors discovered that their earlier proposed structure of epilaurallene must be incorrect. A new isomer of pannosallene, nipponallene (671), along with the novel neonipponallene (672) was isolated from Laurencia nipponica collected off the Russian shore of the Sea of Japan... 

Suzuki M, Mizuno Y, Matsuo Y, Masuda M (1996) Neoisoprelaurefucin, a Halogenated Ci5 Non-Terpenoid Compound from Laurencia nipponica. Phytochemistry 43 121... 

A. I. Usov and M. Ya. Elashvili, Polysaccharides of algae. 44. Investigation of sulfated galactan from Laurencia nipponica Yamada (Rhodophyta, Rhodomelaceae) using partial reductive hydrolysis, Bot. Mar., 34 (1991) 553-560. 

The extraction of the bromoperoxidase from Laurencia nipponica permitted the realization of biosyntheses from laurediols with known configurations and bromide ions in the presence of hydrogen peroxide. In all cases, the products were identical to the natural derivatives (Murai, 1999). Figures 13.28 and 13.29 present some results of these biosyntheses realized from the 6S,7S- and 6R,7R-laurediols. The prevailing experimental conditions influence the composition of the final mixture and yields are low, but these reactions occur only in the presence of bromoperoxidase (Murai, 1999). 

Irie, T, Izawa, M., and Kurosawa, E, (1968) Laureatin, a constituent from Laurencia nipponica Yamada, Tetrahedron Lett., 9, 2091-2096,... 

Furusaki, a., E. Kurosawa, A. Fukuzawa, and T. Irie The Revised Structure and Absolute Configuration of Laurefucin from Laurencia nipponica Yamada. Tetrahedron Letters 1973, 4579. 

Isoprelaurefucin, new Bromo Compound from Laurencia nipponica Yamada. Tetrahedron Letters 1973, 4135. 

Fukuzawa A, Masamune T (1981) Laurepinnacin and isolaurepinnacin, new acetylenic cyclic ethers from the marine red alga Laurenciapinnata Yamada. Tetrahedron Lett 22 4081 1084 Fukuzawa A, Kurosawa E, Tobetsu I (1979) Constituents of marine plants. XXXVI. Laurallene, new bromoallene from the marine red alga Laurencia nipponica yamada. Tetrahedron Lett 30 2797-2780... 

The bromoallene (-)-kumausallene (62) was isolated in 1983 from the red alga Laurencia nipponica Yamada [64a], The synthesis of the racemic natural product by Overman and co-workers once again employed the SN2 -substitution of a propargyl mesylate with lithium dibromocuprate (Scheme 18.22) [79]. Thus, starting from the unsymmetrically substituted 2,6-dioxabicyclo[3.3.0]octane derivative 69, the first side chain was introduced by Swern oxidation and subsequent Sakurai reaction with the allylsilane 70. The resulting alcohol 71 was protected and the second side chain was attached via diastereoselective addition of a titanium acetylide. The synthesis was concluded by the introduction of two bromine atoms anti-selective S -substitution of the bulky propargyl mesylate 72 was followed by Appel bromination (tetrabromo-methane-triphenylphosphine) of the alcohol derived from deprotection of the bromoallene 73. 

Lyakhova EG, Kalinovsky AI, Kolesnikova SA, Vaskovsky VE, Stonik VA (2004) Halo-genated Diterpenoids from the Red Alga Laurencia nipponica. Phytochemistry 65 2527... 

Suzuki, T. and Kurosawa, E. (1979) New bromo acetal from the marine alga, Laurencia nipponica Yamada. 1. Chemistry Letters, 301—304. 

New bisabolane sesquiterpenoids from a variety of plant sources include (95)— (102).59-64 f-y-Bisabolene-8,9-epoxide (103) has been isolated from the alga Laurencia nipponica.65 This compound is possibly the precursor of various halo-genated chamigranes which are abundant in Laurencia algae. 

Full details of an earlier synthesis of chamigrene (161) have been published.95 Further work on the components of the red alga Laurencia nipponica Yamada has resulted in the isolation and structural elucidation (by Y-ray analysis) of the diol (162)96 and spironippol (164).97 The biogenesis of the latter compound can be viewed in terms of an intramolecular cyclization of the diol (163) derivable from the naturally occurring epoxide of 10-bromo-a-chamigrene. 

The absolute stereochemistry of the C-12 and C-13 oxirane moiety of laureoxolane (157), a colorless unstable bromoether obtained from extracts of Laurencia nipponica, was determined on the basis of a chiral synthesis of 156, a degradative derivative of 157. The C-5 to C-8 unit with two asymmetric centers at C-6 and C-7 of 157 corresponds to (25, 35)-l-benzyloxy-3,4-epoxy-2-butanol (142). Elongation of 142 using butyllithium and copper cyanide followed by the creation of a new epoxide provides 152. Lithium acetylide ethylenediamine complex addition to 152 and subsequent ketalization affords the acetylenic acetonide 153, which is coupled with (2i ,35)-l,2-epoxy-3-benzoyloxypentane (154) to furnish 155. Subsequent five-step transformation of 155 provides 156 [60] (Scheme 37). 

Carbon skeleton of seco -chamigrane This skeleton is also poorly represented among Ceramiales, with fewer than a dozen structures having been isolated from the species Laurencia nipponica... 

A small number of sesquiterpenes with this new chamigrane derivative skeleton-spironippol, pannosa-nol, pannosane, scopariol, and 2-bromospironippol-were isolated from the Japanese species Laurencia nipponica (Fukuzawa et al., 1981b), the Malaysian species Laurencia pannosa (Suzuki et al., 2001), the Brazilian species Laurencia scoparia (Davyt et al., 2001), and the Chinese species Laurencia composita (Ji et al., 2009b), respectively. 

Many biogenetic schemes have been proposed to explain the formation of these compounds which all involve, as a starting point, four eneynediols with 15 carbon atoms, which are themselves derived from a common intermediate, acid 4,7,10-16 3 (16 3 n-6). The diols later turn into two other eneynediols, 3E- and 3Z-laurediols, which are regarded as the real precursors of aU the cyclic ethers. This hypothesis, presented in Figure 13.26, was corroborated by the discovery of laurediols, then of four eneyne-diol intermediates, in a Japanese variety of Laurencia nipponica (Kurosawa, Fukuzawa, and Me, 1972 Fukuzawa et al., 1993 Suzuki et al., 2009). 

Fukuzawa, A., Shea, C.M., Masamune, T., Furusaki, A., Katayama, C., and Matsumoto, T. (1981b) Spironippol new sesquiterpene from the marine alga Laurencia nipponica Yamada. Tetrahedron Lett., 22, 4087-4088. 

Kikuchi, H., Suzuki, T., Kurosawa, E and Suzuki, M. (1991) The structure of notoryne, a halogenated Cjs nonterpenoid with a novel carbon skeleton from the red alga Laurencia nipponica Yamada. Bull. 

Suzuki, T., Koizumi, K., Suzuki, M., and Kurozawa, E. (1983a) Constituents of marine plants. 56. KumausaHene, a new bromoallene from the marine red alga Laurencia nipponica Yamada. Chem. Lett., 12, 1639-1642. 

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