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Photochemische Reaktionen 30. Mitteilung. Die UV.‐Bestrahlung von 3β‐Hydroxy‐11‐oxo‐lanostan
Author(s) -
Altenburger E.,
Wehrli H.,
Schaffner K.
Publication year - 1965
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.19650480406
Subject(s) - chemistry , yield (engineering) , acetylation , lanostane , derivative (finance) , ketone , alcohol , irradiation , medicinal chemistry , ultraviolet , stereochemistry , organic chemistry , biochemistry , pathology , medicine , materials science , alternative medicine , physics , economics , financial economics , nuclear physics , metallurgy , triterpene , gene , quantum mechanics
Upon irradiation of an ethanolic solution of 3β‐hydroxy‐11‐oxo‐lanostane(1) with ultraviolet light and subsequent acetylation of the crude reaction mixture, a single tertiary alcohol, the 11,18‐cyclobutanol derivative 4 , could be isolated in about 40% yield (corrected for recovered starting material). According to previous findings[4] and in contrast to this result, the steroidal 4,4‐dimethyl‐ketone 15 is exclusively converted into the 11,19‐cyclobutanol 16 . It is assumed that the additional methyl group in the 14α position of 1 causes this shift of the selective attack in the photo‐chemical cyclization process from CH 3 ‐19 to CH 3 ‐18.