Of bastadin

Pettit GR, Butler MS, Bass CG, DoubekDL, Williams MD, Schmidt JM, Pettit RK, Hooper JNA, Tackett LP, Filiatrault MJ (1995) Antineoplastic Agents, 326. The Stereochemistry of Bastadins 8, 10, and 12 from the Bismark Archipelago Marine Sponge Ianthella basta. J Nat Prod 58 680... 

Masuno MN, Pessah EM, Olmstead MM, Molinski TF (2006) Simplified Cyclic Analogues of Bastadin-5. Structure-Activity Relationships for Modulation of the RyRl/FKBP12 Ca+2 Channel Complex. J Med Chem 49 4497... 

Kotoku N, Tsujita H, Hiramatsu A, Mori C, Koizumi N, Kobayashi M (2005) Efficient Total Synthesis of Bastadin 6, an Anti-Angiogenic Brominated Tyrosine-Derived Metabolite from Marine Sponge. Tetrahedron 61 7211... 

C-14 and C-29 to C-33. The structures of the bastadins have in most cases been elucidated through the application of standard spectroscopic techniques, although those of bastadin 4 and the tetramethyl ether of bastadin 5 have been established through X-ray crystallography [119]. 

Scheme 9.12 Kobayashi and coworkers total synthesis of bastadin 6 [144],...

Yamamura and coworkers have used a thallium trifluoroacetate mediated oxidative cyclization in their synthesis of aerothionin and related products and also in the synthesis of bastadin-6, a 28-membered ring lactone. 

SCHEME 164. Synthesis of bastadin-6 using TTN-mediated oxidation as a key step... 

Nishiyama, S, and Yamamura, S, (1982) Total synthesis of bastadins. Tetrahedron Lett., 23, 1281-1284. 

Couladouros, E.A. and Moutsos, V.l. (1999) A general synthetic route towards bastadins. Part 1 synthesis of the eastern part of bastadins 4-16. Tetrahedron Lett., 40, 7023-7026. 

Bailey, K.L. and Molinski, T.F, (2002) Synthesis of bastadin analogs through an SNAr coupling strategy. Tetrahedron Lett., 43,9657-9661. 

Couladouros, E.A., Moutsos, V.I., and Pitsinos, E.N. (2003) Synthesis of o-brominated diaryl ethers using symmetrical iodonium salts application to the synthesis of bastadin precursors. ARKIVOC, 92-101. 

Kotoku, N., Tsujita, H., Hiramatsu, A., Mori, C Koizumi, N and Kobayashi, M. (2005) Efficient total synthesis of bastadin 6, an anti-angiogenic brominated tyrosine-derived metabolite from marine sponge. Tetrahedron, 61, 7211—7218. 

The studies of bastadins 8-13 were published simultaneously, unfortunately leading to the assignment of the same number to different bastadins. Scheuer et al. suggested that these alkaloids be renamed in the order of when they were received for publication. Thus, bastadins-8 to -11 of Pordesimo and Schmitz (132) retained their original numbering, bastadin-9 of Miao et al. (142) was renumbered as bastadin-12 (bastadin-8 from Miao et al. coincidentally has the same structure as bastadin-8 of Pordesimo and Schmitz), and bastadin-12 of Butler et al. (131) became bastadin-13. 

Selected H-NMR Data of Bastadin Tetra-0-methyl Ethers 130). 

Guo et al. developed a chemoenzymatic strategy for the synthesis of bastadins-2, -3, and -6 (232). The requisite dimeric dityrosine and isodityrosine were successfully prepared by C-C and C-O oxidative phenolic coupling of mono- and dihalogenated derivatives of tyrosine and tyramine using horseradish (233) and soybean peroxidases. 

Couladouros and Moutsos reported a general synthetic route for the synthesis of the eastern and western parts of bastadins, which can be used for construction of bastadins 4—16 (234-236). The brominated biaryl ethers are synthesized using the iodonium salt method. The eastern segment 352 was synthesized within 18 steps in 15.5% overall yield. The western segment 353 and 354, which can be used to construct bastadins-8 (212), -10 (214), -12 (216), and -17 (221), was synthesized in 13 steps (see the following scheme). 

In order to utilize the hydroxyl group as a general precursor for aU functionalities present at C-5 and C-6 of the bastadins, 355 was transformed after desilylation either to alkene 356 or alkane 357 using DBU or NaBH4, respectively, providing the necessary intermediates for the construction of bastadins-4 to -7 (208-211), -9 (213), -11 (215), and -14 to -16 (218-220). 

Molinski et al. also reported the reduction of bastadin-4 (208) to bastadin-5 (209) using cationic hydrogenation (EtsSiH, TFA, 60%) (240). Specific deuteration at H-5 of bastadin-5 was conducted following this method. 

Leone-Stumpf and Lindel synthesized the ruthenium labeled western (383) and eastern (384) diaryl ether and tripeptide (385) of bastadin-5, and for the first time established an HPLC method using aminopropyl-functionalized silica to purify the [CpRu] complexes (241,242). 

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