Studies towards the total synthesis of halichlorine: asymmetric synthesis of the spiroquinolizidine subunit
摘要:
The C1-C15 spiroquinolizidine subunit (cf. 2) of the marine natural product halichlorine (1) was prepared in 12 steps starting from the known 'Meyers-lactam' 5. The synthesis involves a B-alkyl-Suzuki coupling followed by a highly stereoselective intramolecular Michael addition and an intramolecular Mannich ring closure. (C) 1999 Elsevier Science Ltd. All rights reserved.
Studies towards the total synthesis of halichlorine: asymmetric synthesis of the spiroquinolizidine subunit
摘要:
The C1-C15 spiroquinolizidine subunit (cf. 2) of the marine natural product halichlorine (1) was prepared in 12 steps starting from the known 'Meyers-lactam' 5. The synthesis involves a B-alkyl-Suzuki coupling followed by a highly stereoselective intramolecular Michael addition and an intramolecular Mannich ring closure. (C) 1999 Elsevier Science Ltd. All rights reserved.
Studies towards the total synthesis of halichlorine: asymmetric synthesis of the spiroquinolizidine subunit
作者:Dirk Trauner、Samuel J Danishefsky
DOI:10.1016/s0040-4039(99)01170-3
日期:1999.9
The C1-C15 spiroquinolizidine subunit (cf. 2) of the marine natural product halichlorine (1) was prepared in 12 steps starting from the known 'Meyers-lactam' 5. The synthesis involves a B-alkyl-Suzuki coupling followed by a highly stereoselective intramolecular Michael addition and an intramolecular Mannich ring closure. (C) 1999 Elsevier Science Ltd. All rights reserved.
Concise Stereoselective Routes to Advanced Intermediates Related to Natural and Unnatural Pinnaic Acid This work was supported by the National Institutes of Health (Grant Numbers: CA28824). Postdoctoral Fellowship support is gratefully acknowledged by M.W.C. (U.S. Army BCRP, DAMD17-98-1-8154), M.F.H. (5T32 CA62948-05), and D.T. (Schering Research Foundation, Berlin). We thank Dr. George Sukenick of the MSKCC NMR Core Facility for NMR and mass spectral analyses.
作者:Matthew W. Carson、Guncheol Kim、Martin F. Hentemann、Dirk Trauner、Samuel J. Danishefsky
The diastereoselective addition of the highly functionalized organozinc compound 1 to the aldehyde 2 in the presence of the chiral amino alcohol 3 (-->4) is a key step in the first total synthesis of (+)-halichlorine. A series of protections/deprotections and a macrolaconization complete the synthesis. Halichlorine selectively inhibits the expression of the cell adhesion molecule VCAM-1. TBS=tert-butyldimethylsilyl.