13901-20-7Relevant articles and documents
Stereochemistry and Regiochemistry of Electron Impact, Photolytically, and Thermally Induced Eliminations from 5α-Cholestanyl Acetates
Valente, C.,Eadon, G.
, p. 44 - 51 (1984)
Deuterium-labeled compounds were used to define the sterochemistry and regiochemistry of the electron impact induced eliminations of acetic acid from 5α-cholestanyl 3α-acetate, 4α-acetate, and 6α-acetate.Comparison of the electron impact induced eliminations to the pyrolysis and to the photolysis of the corresponding phenylacetates confirmed that the mass spectral elimination was a stepwise process proceeding through the stable chair conformation of the steroid's cyclohexyl ring.The equatorially oriented 4α- and 6α-acetates fragmented with predominant loss of asecondary trans-equatorial hydrogen, rather than the tertiary cis-axial hydrogen, despite the a priori greater migratory aptitude of tertiary hydrogens.The electron impact induced fragmentation of the 3α-acetate occured with predominant loss of a C-4 hydrogen; in contrast, the photolysis of the corresponding 3α-phenylacetate results in loss of a C-2 hydrogen.This results can be attributed to the reversibility of the photolytically induced hydrogen-abstraction step.
Stereocontrolled formation of cis and trans ring junctions in hydrindane, decalin, and steroid systems by palladium-catalyzed regioselective and stereospecific hydrogenolysis of allylic formates
Mandai, Tadakatsu,Matsumoto, Takaji,Kawada, Mikio,Tsuji, Jiro
, p. 5483 - 5493 (1993)
Both the cis and trans ring junctions can be generated selectively in hydrindane, decalin and steroid systems by the palladium-catalyzed regioselective and stereospecific decarboxylation-hydrogenolysis of allylic formates. The trans junctions were formed from 3β allylic formates of decalin and steroid and 5β allylic formates of hydrindane. The corresponding 3α and 5α formates generate the cis ring junction.
