ISSN:
0009-2940
Keywords:
Steroids
;
Androsta-1,4-diene-3,17-dione
;
Conjugate addition
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
By a variation of the nature of the reagent system conjugate addition to the cross-conjugated steroidal dienone 1 occurs selectively either at C-1 or at the sterically hindered C-5. With Me3Al or Me4AlLi in the presence of catalytic amounts of Cu1 salts, a high regioselectivity (up to 97:3) in favour of position 1 is achieved. Application of ate complexes of aluminium and titanium in the presence of Ni(acac)2 as catalyst, however, leads to a reversal of the regioselectivity in favour of position 5 (up to 11:89). Aluminium and titanium ate complexes are efficient reagents in the Ni(acac)2-catalysed conjugate addition to sterically hindered enones.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19961290814
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