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Synthesis and circular dichroism of steroids with a 1,4‐benzodioxane chromophore: On the absolute configuration of (−)‐silandrin
Author(s) -
Antus Sándor,
BaitzGács Eszter,
Snatzke Günther,
Tóth Tamás S.
Publication year - 1991
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.1991199101115
Subject(s) - absolute configuration , helicity , chromophore , circular dichroism , chemistry , cotton effect , spectral line , stereochemistry , crystallography , chirality (physics) , organic chemistry , physics , chiral symmetry , quantum mechanics , nambu–jona lasinio model , quark
Starting from cholesterol the three possible stereoisomeric 1,4‐benzodioxanes 24, 31, 32 and a series of analogues with 2βH,3βH configuration ( 25–27, 29, 30 ) have been synthesized. The α band of the 1,4‐benzodioxane chrompohore has been unequivocally identified in the CD spectra between 325–300 nm. For its Cotton effect the same helicity rule is valid as for homochirally analogous tetralins: the P/M helicity of the heteroring leads to a positive/negative CD within the α‐band. The (2′ R ,3′ R ) configuration of 6 has been established by a comparison of its CD data with those of 39 and with the help of the above‐mentioned helicity rule. This allows the assignement of the (2 S ,2′ R ,3′ R ) configuration of (−)‐silandrin ( 3 ).