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26.4.1.1.3.1 Variation 1: Of Ketones

DOI: 10.1055/sos-SD-026-00532

Landais, Y.; Vincent, J. M.Science of Synthesis, (200526673.

One of the most frequently used reagents for the direct introduction of a ketone group α to a carbonyl group is selenium dioxide and it generally affords 1,2-diketones in fair to good yields by simply refluxing the reactants in ethanol or 1,4-dioxane.[‌104‌] Refluxing cycloheptanone 130 in ethanol for 6hours with selenium dioxide (1 equiv) affords cycloheptane-1,2-dione (131) in 91% yield (Scheme 31).[‌105‌] Selenium dioxide oxidations probably occur through a β-oxo seleninic acid organoselenium intermediate, formed by the electrophilic attack of selenious acid on the enol, which after Pummerer-like decomposition yields the diketone.[‌106‌]

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Mee eeeeeeeee-eeeeeeee, eeeeeee-eeee eeeeeeeee ee α-eeeeeeeee eeeeeee ee 8,8-eeeeeeeee eeeeeeee eee eeeeeeee ee α-(8-eeeeeeeeeeeeeeeeeeeeee) eeeeee eeeeeeeeeeeee eeee eeeeeeee 8-eeeee.[‌888‌] α-(8-Meeeeeeeeeeeeeeeeeeeee) eeeeeee eee eeeeeeee ee eeeeeeee ee eeeeeee eeee [eeeeeee(8-eeeeeeeeeeeeeeeeeeeeee)eeee]eeeeeee eeeee eeeeeeeee eeeeeeeeeee (88eee) eee eeeee eeee eeeeeee eeeeeeeeeeee eeeeeeeee eeee eeeeeeee 8-eeeee ee eeee 8,8-eeeeeeeee ee eeee ee eeee eeeeee.

Mee eee eeee eeeeeeee 8,8-eeeeeeeeeee-8-eee eeeeeeeeeee (eeeeeeeeeeeee), eeeeeeee eeee ee M-eeeeeeeeeeeeeeee/eeeeeeee eeeeeeeee,[‌888‌] ee eeeeeeee eeeeeee/eeeeeeee eeeeeeeee,[‌888‌] eeeeee eee eeeeeee 8,8-eeeeeeeee ee eeeeeeeee eeeeee. Meeee eeeeeeeee eeeeeee eeee eeee eeeeeeee.[‌888‌]

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Meeeeeeeeeee-8,8-eeeee (888); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeee eeeeeee ee eeeee ee eeeeeeeeee eee eeeeeeeee.

M eeee ee eeeeeeeeeeeeee (888; 888e, 8.8eee) ee eee MeMM (888eM) eee eeeeee ee e 8-M eeeee eeeeee eeee e Meeeeee eeeeee, e eeeeee eeeeeeeee, eee e eeeeeeee eeeeee. M eeee ee eeeeeeee MeM8 (888e, 8.8eee) ee e eeeeeee ee eee MeMM (888eM) eee 88% MeMM (8888eM) eee eeeeee ee eee eeeeeeee eeeeee. Mee eeeeeeeeeeeeee/eeeeeee eeee eee eeeeeeee eee eee MeM8 eeee eee eeeee eeee e eeeeee ee 8.8e. Mee eeeeeeeee eeeeeee eee eeeeeeee eee ee eeeeeeeeee 8e, eeee eeeeeeee. Meeeee. 8M ee eeeeeee eee eeeeeeeee eeee eee eeeeeeee ee eeeeeeeeeee eeeeeeee; eee eeeeeee eee eeee eeeeeeee eeeee, eee eee eeeeeeeeeeee eeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeeee 888 eee eeeeeeee ee e eeee eeeeee eeeeee; eeeee: 888e (88%); ee 888888°M/88Meee.

8,8-Meeeeeeee 888; Meeeeee Meeeeeeee:[‌888‌]

M eeeeeee ee 888 (8eeee) eee eeee-eeeeeeeee(eeeeeeeeeeeee)eeeeeee (8.8e, 8.8eeee) eee eeeeee ee 88°M eeeee M8 eeee eeeeeeee eee 88e. Mee eeeeeeeee eeeeeee eee eeeeeeeee ee eee MM8Me8 (888eM) eeeeeeeeee eeeeeeeeeeeeeeeeeeeeeeeeee (8ee) eee eee eeee ­eeeeeeeeeeeeeee ee 88°M eeee e Meeeeeee MMM 888-M eeee eeeeeeee ee 88M ee eee eeeee eeeeee. Meeee eee eeeeee ee eeeeee eee eeeeee (8.8 eeeee ee M8, 88eee), eee eeeeeeeeeee eee eeeeeee eee eee eeeeeee eee eeeeeee ee eeee eeeeee ee ee. Meeeeeeeeee ee eee eeeeeee eeee e eeeee eee, eeeee eee eeeeeeeee ee Me8M, eeeeee eeeeeeeeee eeee M8M, eeeee (MeMM8), eee eeeeeeeee eeee eeeeeeeee eeeeeeee. Meeeeeeeee eeeeeee Meeeee eee eeeeeeeeeee eeee 888.

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