Marine alkaloids synthesis enantioselective

Enantioselective total synthesis of marine alkaloids, manzamine A, and related compounds 00JHC567. 

An enantioselective total synthesis of (+)-ptilocaulin (79), a marine alkaloid with high antimicrobial and cytotoxic activity, was reported by Schmalz (Scheme 14) [40, 41]. The synthesis starts from anisole-Cr(CO)3, which is converted to the planar-chiral building block 74 with >99% ee by enantioselective deprotonation/silylation [42] and subsequent recrystallization. After attachment of a 2-butenyl side-chain ( 75) [43], nucleophilic addition of 2-lithio-l,3-... 

Very recently, the total synthesis of marine alkaloids ent-flustramines A and B and c t-flustramides has been achieved using a Pd-catalyzed asymmetric prenylation of oxindoles. Initially, Trost and co-workers investigated the regioselective and enantioselective prenylation of a variety of oxindoles for the preparation of prenylated or reversed-prenylated 3,3 -disubstituted oxindole derivatives. The... 

Toyooka N, Okumura M, Takahata H. Enantioselective total synthesis of the marine alkaloid lepadin B. J. Org. Chem. 1999 64(7) 2182-2183. 

Toyooka, N., Yotsui, Y, Yoshida, Y, Momose, T. and Nemoto, H. (1999) Highly stereoselective construction of 4,6-cis-substituted quinolizidine ring core an application to enantioselective total synthesis of the marine alkaloid davipectines A. B and pictamine. 

Norzoanthamine is a heptacychc alkaloid originally isolated from marine zoanthids. In addition to its complex molecular structure, norzoanthamine is well-known for its potent antiosteoporotic activity. In their studies toward the total synthesis of norzoanthamine, Yang and co-workers developed a 12-step enantioselective synthesis of the highly functionalized and stereochemically complex ABC ring system. A transannular Michael reaction cascade was... 

---