Photochemical and Beckmann rearrangement of (Z)-cholest-4-en-6-one oxime

• Main Authors: VLADIMIR D. PAVLOVIC, LJUBINKA B. LORENC, MILAN M. DABOVIC, MIRA S. BJELAKOVIC, NATALIJA M. KRSTIC
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2004-06-01
• Series: Journal of the Serbian Chemical Society
• Subjects: (Z)-cholest-4-en-6-one oxime; 7-aza-B-homocholest-4-en-6-one; Beckmann rearrangement; photoreaction
• Online Access: http://www.shd.org.yu/HtDocs/SHD/Vol69/No6/V69-No6-01.pdf

Beckmann rearrangement of (Z)-cholest-4-en-6-one oxime (4) (prepared in 4 steps starting from cholest-5-en-3b-ol (1)) with thionyl chloride in dioxane solution afforded an enamide-type lactam, i.e., 7-aza-B-homocholest-4-en-6-one (6) as a single product. Photoreaction of the same compound in methanol or benzene-acetic acid solution gave a mixture of products, with the formation of the parent ketone 3 and the occurrence of Z/E isomerization, while the lactam 6 was obtained only when the reaction was performed in methanol and then in very low yield (7 %).