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Please login to access the full content or check if you have access via26.9.1.1.1.3 Variation 3: Allylic Oxidation with Selenium Reagents
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Marsden, S. P., Science of Synthesis, (2005) 26, 1047.
Selenium dioxide is a popular reagent for the formation of allylic alcohols by allylic oxidation, as the reactions proceed without C=C bond migration and offer high and predictable regioselectivity.[13] Occasionally, direct conversion of an alkene into an unsaturated ketone is observed, though often this is formed as a mixture with the alcohol. For example, oxidation of 10 gives a mixture of ketone 11 and alcohol 12 (Scheme 3).[14] The ketones are presumed to be formed via the alcohol since the regioselectivities observed mirror those for the normal oxidation. Although benzeneseleninic anhydride is not generally active toward allylic oxidation, the corresponding 2-pyridyl reagent, which is generated in situ from di-2-pyridyl diselenide (14) and iodylbenzene, effects clean oxidation of alkenes to enones (e.g., 13 to 15), again apparently proceeding through the intermediate allylic alcohol.[15]
Meeeee 8 Meeeeee Meeeeeeee eeee Meeeeeee Meeeeeee[88,88]
Meeeeeeeeeee Meeeeeeee
(+)-Meeeeeeeeee (88); Meeeeee Meeeeeeee:[88]
MMMMMMM: Meeeeeeeeeee ee eeeeeeeeeee eeeeeeeee eee eeee eeeeee ee eeeee eeee eeeeeee eee eeeeeeee eeee eeeeeeee.
MeMM8 (8.88 e, 8 eeee) eee ee-8-eeeeeee eeeeeeeeee (88; 88 ee, 8.8 eeee) eeee eeeee eeeeeeeeeeee ee e eeee ee β-eeeeee (88; 8.88 e, 8 eeee) ee eeeeeee (88 eM) (MMMMMMM: eeeeeeeeee) eee eee eeee eeeeeeee eeee eeeeeeee eeeee M8. Meeee 8.8 e, eee eeeeeee eee eeeeee ee ee, eeeeeeee eeeeeee Meeeee, eee eeeeeeeeee ee eeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MM8Me8); eeeee: 8.88 e (88%).
References
[13] | Meeeeee, M., Mee. Meeee. (M. M.), (8888) 88, 888. |
[14] | Meeeeeee, M.; Meeeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[15] | Meeeee, M. M. M.; Meeee, M., Meeeeeeeeee, (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) M 88-8, 8888.
- 8.Meeeee-Meee, (8888) M 88-8, 8888.
- 8.Meeeee-Meee, (8888) M 88e8, 88.