A concise and stereoselective synthesis of the brassinolide and related compounds' side chains

Tetrahedron Letters

Volumn 44, Issue 20, 2003, Pages 3991-3993

  Peng, Lizeng ^a   Li, Yulin ^a   Li, Weidong Z ^a  

^a LANZHOU UNIVERSITY   (China)

Author keywords

[No Author keywords available]

Indexed keywords

6BETA METHOXY 3ALPHA,5 CYCLO 5ALPHA PREGNANE 20 CARBOXALDEHYDE; ALPHA SILOXYKETONE; ANION; BRASSINOLIDE; CHEMICAL COMPOUND; KETONE DERIVATIVE; UNCLASSIFIED DRUG;

ALDOL REACTION; ARTICLE; CHEMICAL PROCEDURES; CHEMICAL STRUCTURE; HORMONE SYNTHESIS; STEREOCHEMISTRY;

EID: 0037433831     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(03)00691-9     Document Type: Article

References (18)

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7. 1H NMR evidence is in accord with this since coupling constant between H-22 and H-23 in 22R,23R isomer 14 (J=3.6 Hz) indicates the preferred conformation for the side chain shown. For the 22R,23S 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°.
8. 1H NMR evidence is in accord with this since coupling constant between H-22 and H-23 in 22R,23R isomer 14 (J=3.6 Hz) indicates the preferred conformation for the side chain shown. For the 22R,23S 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°.
9. 7a.
10. 7a.
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18. ++H) 433.3683, found 433.3676.