Synthesis of the (+)-C26–C40 Domain of the Azaspiracids by a Novel Double Intramolecular Hetero-Michael Addition Strategy This work was supported by the United States National Institute of Environmental Health Sciences (NIEHS; grant number ES10615), NIH, and by Bristol-Myers Squibb (CJF). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH, or BMS. We thank Dr. A. B. Dounay and Dr. G. Florence for critical reading of the manuscript.
Oxazoline N-Oxide-Mediated [2 + 3] Cycloadditions: Application to a Total Synthesis of the Hypocholesterolemic Agent 1233A
摘要:
Oxetanone 1233A1 has been synthesized in 22 steps and 3.43% overall yield from 3-methylglutaric anhydride. Asymmetric carbon at C-7 was introduced by a diastereoselective esterification of 3-methylglutaric anhydride, whereas the two asymmetric carbons at C-2' and C-3' were controlled by an asymmetric [2 +/- 3] cycloaddition using camphor-derived oxazoline N-oxide as dipole.
Synthetic Studies on Azaspiracid: Synthesis of Key Intermediate for the Construction of the FGHI Ring System
作者:J. Yadav、C. Venugopal
DOI:10.1055/s-2007-985585
日期:——
the FGHI ringsystem of azaspiracid is -described. The synthesis features the desymmetrization strategy for the construction of the C27-C33 fragment, Masamune-Roush coupling conditions for the C33-C34 bond formation, and Sharpless asymmetric dihydroxylation as the key steps. One more important feature of this synthetic route is that we can synthesize other -enantiomers of the FGHI ringsystem by changing