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Synthesis, Structure, and Reactivity of Secosteroids Containing a Medium‐Sized Ring. Part 36. Transannular photocyclization of some unsaturated 5,10‐secosteroidal ketones: A reevaluation
Author(s) -
Heckendorn Roland,
Fuhrer Hermann,
Kalvoda Jaroslav,
Lorenc Ljubinka,
Pavlović Vladimir,
Mihailović Mihailo Lj.
Publication year - 1995
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19950780519
Subject(s) - oxetane , chemistry , intramolecular force , reactivity (psychology) , ring (chemistry) , stereochemistry , irradiation , transformation (genetics) , medicinal chemistry , organic chemistry , biochemistry , pathology , nuclear physics , gene , medicine , physics , alternative medicine
The structures 9 and 8 are proposed for the single isolated irradiation product of 5‐oxo‐5,10‐secocholest‐1(10)‐en‐3α‐yl acetate ( 6 ) [2] and for the minor product of irradiation of 5‐oxo‐5,10‐secocholest‐1(10)‐en‐3β‐yl acetate ( 1 ) [3], respectively. These compounds are formed in an alternative reaction with respect to the originally observed intramolecular Paterro ‐ Büchi photoprocess (transformation of 1 to oxetane 2 ). The formerly postulated ‘active’ conformations for 1 and 6 still allow explanation of their generation.