Novel construction of brassinolide and the related compounds' side chains

Acta Chimica Sinica

Volumn 61, Issue 7, 2003, Pages 1052-1057

  Peng, Li Zeng ^a   Zhang, Tao ^a   Mei, Tian Sheng ^a   Zhang, Feng Zhi ^a   Li, Yu Lin ^a  

^a LANZHOU UNIVERSITY   (China)

Author keywords

Aldol reaction; Brassinolide; Side chain

Indexed keywords

EID: 33745056617     PISSN: 05677351     EISSN: None     Source Type: Journal    
DOI: None     Document Type: Article

References (18)

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5. For recent synthetic work on cembranolides using methyl isopropyl ketone and its derivative to found 20-membered carbon chain from this laboratory, see: (a) Li, W. D. Z.; Li, Y.; Li, Y. L. Tetrahedron Lett. 1999, 40, 965.
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9. 1H NMR evidence is in accordance with this since coupling constant between H-22 and H-23 in 22R, 23S isomer 15 (J = 3.6 Hz) indicates the preferred conformation for the side chain shown. For the 22R, 23R isomer 7 the corresponding couping constant (J = 8.8 Hz) indicates a preferred conformation for the side chain in which the dihedral angle between H-22 and H-23 is about 180°.
10. The migration of TBS group from α-oxygen to β-oxygen is a novel phenomenon in directed aldol reaction. We will describe the phenomenon in detail in a future paper.
11. For examples, see: (a) Lee, A. W. M.; Martin, V. S.; Masamune, S.; Sharpless, K. B.; Walker, F. J. J. Am. Chem. Soc. 1982, 104, 3515.
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14. (b) McMorris, T. C.; Chavez, R. G.; Patil, P. A. J. Chem. Soc., Perkin Trans. 1 1996, 295.
15. For a recent review of Mukaiyama aldol reaction, see: Mahrwald, R. Chem. Rev. 1999, 99, 1095.
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