Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
26.1.1.3.2 Method 2: Oxidative Deprotection of Silyl Ethers

DOI: 10.1055/sos-SD-026-00003

von Angerer, S.Science of Synthesis, (200526111.

Trialkylsilyl groups are widely used as protecting groups for alcohols. If the protected alcohol needs to be converted into a ketone or aldehyde, a one-step or one-pot reaction including both deprotection and oxidation would be desirable. A variety of methods have been elaborated that achieve this goal and are the subject of a review article.[‌8‌] Some of the oxidation procedures described previously can also be applied to the oxidation of silyl ethers if these alcohol derivatives are susceptable to cleavage under the reaction conditions. Trimethylsilyl ethers of nonactivated secondary alcohols can be oxidized to the corresponding ketones with chromium(VI)-based reagents such as the Jones reagent.[‌75‌,‌76‌,‌413‌,‌431‌‌434‌] A more powerful oxidant has been obtained by the combination of Jones reagent with potassium fluoride.[‌435‌] The fluoride ion probably facilitates the cleavage of the SiO bond. A typical example of this reaction is the formation of (5S)-3,3,5-trimethylcyclohexanone (166) (Scheme 118).

Meeeee 888 Meeeeeeee Meeeeeeeeeee eeee Meeeeeee(MM) Meeee ee eee Meeeeeee ee Meeeeeee[‌888‌]

Meeeeee eee ee eeeeeee eee eeeeeeeee eeeee ee eeeeeeee(MM) ee ee eee eeeeeeee ee eeeeee­eeeeeeeeeeeeeee ee eeeeeeeeee eeeeeeeeee. Meeeeee eeeeeeeeeeeee eeeeee eeee eeee eeeeeeeeeee eeeeeeeee eeee eeeeeee eeee eeee eeeeeee.[‌888‌] Meeeeeee eeeeee(MM) eeeeeee eeeeeeeee eeeeeeeee eeeeeeee ee eeeeee eeee eeeeee eeeeeee ee eee eeeeeeeeee ee eeeeee eeeeee eee eee eeee ee eeeeeeeee eeee eeeeeeeeeeeeee eeeeee ee eeeeeeeee eeeeeeee.[‌888‌] Meeeeeeee eeeeeeee eeeeeeeee eeeeeeee (Meeee eeeeeee) eee eeee eeeeeee eeeeeeeee- eee eeeeeeeeeeeee eeeeee eee eee eeeeeeeeee eeeeeee eeee-eeeeeeeeeeeee- eee eeee-eeeeeeeeeeeeeeeeee eeeeee.[‌888‌,‌888‌] Meee, eeee eeeeee eeeeee eee eeeeeeeee eeeeeeeee ee eeeeeeeeeee eeeeeeeee eeeeeeee. Me eeeeeeeeeee eeeeeeeee eeeeee eee eeeeeeeee eeeeeeeeeeeeee eeeeee ee eeee-eeeeeeeeeeeeeeeeee ee eee eeeeeeee ee eee(eeeeeeeeeeeeeee) eeeeeeee, ee eeeee ee eee eeeeeeeee ee (8M)-8,8,8-eeeeeeeeeeeeeeeeeee eeeeeeeeeeeeee eeeee ee (8M)-8,8,8-eeeeeeeeeeeee (888) (Meeeee 888).[‌888‌]

Meeeee 888 Meeeeeeeee ee e Meeeeeeeeeeeee Meeee eeee e Meeeee eeee eeee-Meeee Meeeeeeeeeeee eee Mee(eeeeeeeeeeeeeee) Meeeeeee ee eee Meeeeeee.[‌888‌]

Meeee MM eeeeeeeeeee, 8,8-eeeeeeee-8,8-eeeeeeeeeeee-8,8-eeeeeee eeeeeeee eeeeeeeeeeeeee eeeeee ee eeeeeee eee eeeeeeee eeeeeeee ee eee eeeeeeeeeeeee eeeeeeee eeeeeeeee.[‌888‌] Me ee eeeeeeeee eeee eee MeMM eeee ee eeeeeee ee eeeeee ee eeee ee eee eeeeeee eeeee ee eee eeeeeeeee eeeeeeee. Me eeeeeee ee eeee eeeeeeeeeeeee eeeeeeeee ee eee eeeeeeeeeee ee eee-8-ee-8-eee (888) (Meeeee 888).

Meeeee 888 Meeeeeeee ee ee Meeee Meeeeeeeeeeeee Meeee eeee 8,8-Meeeeeee-8,8-eeeeeeeeeeee-8,8-eeeeeee eeeee Meeeeeeeeee[‌888‌]

Mee ee eee eeeeeeeeee eee eee eeeeeeeee ee eeeeeeeeeeeee eeeeee eeeeeeee eeeeeee eeeeeeeeeee, eeeee eee ee eeeeeeeeeeee ee eeeeeeee eeee eeeeeeeeeeeeeeeeee eeeeeeeeeeee.[‌888‌,‌888‌] Me eeeeeee ee eee eeeeeeeeee ee eeeeeeeeee eeeeeeeeeeeeee eeeee eeee eeeeeeeeeeeee ee 88% eeeee eeee eeee eeeeeeeeee eeeeeee. Mee e eee-eee eeeeeeeeeeee eee eeeeeeeee eeeeeeee ee eeee-eeeeeeeeeeeeeeeeee eeeeee ee eeeeeeee, 8-eeeeeeeeeeeeeee ee eee eeeeeeee ee eeeeeeeee eeeeeeeeee ee eee(eeeeeeeeeeee)eeeeeeeeeeeeeeeee(MM) eee eeee eeeeeee.[‌888‌] Mee eeeeeeee eeeeeeeee eee eeeeeeee ee eeee eeeeee.

Meeeeeeeeeee Meeeeeeee

(8M)-8,8,8-Meeeeeeeeeeeeeeeeee-8-eee (888); Meeeeee Meeeeeeee:[‌888‌]

Me e eeee ee (8M)-8-(eeee-eeeeeeeeeeeeeeeeeee)-8,8,8-eeeeeeeeeeeeeeeeeeee (8eeee) ee eeeeeee (88eM) ee 8°M eeee eeeee MM (8eeee) eee 8M Meeee eeeeeee (8eM). Mee eeeeeee eee eeeeeee ee 8°M eee 8e, eeeeeee eeee M8M (88eM), eee eeeeeeeee eeee MM8Me8 (8×88eM). Mee eeeeeee eeee eee eeeeee eeee M8M, eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee. Meeeee eeeeeeeeeeeeee ee eee eeeeeee [eeeeee eee (88e), eeeeeeeee eeeee/MeMMe 8:8] eeee eee eeeeeee; eeeee: 888ee (88%).

(8M)-8,8,8-Meeeeeeeeeeeeeeeeee-8-eee (888) ee Meeeeeeee eeee Mee(eeeeeeeeeeeeeee) Meeeeeee eee eeee-Meeee Meeeeeeeeeeee[‌888‌]

MMMMMMM: Mee eeeee-eeeee eeeeeeeeeee, ee ee eeeeeeeee ee eeeeee eeeee eee eeeeeee ee eeeeeeee eeeeeeee eeeeee eeeeeeee eee eeeeeeee ee eeeeee ee eeee eeeeeee Me8MM8.

Me ee eeee eeeee-eeeeeeee eeeee eeeeeeeeee e eeeeeee eeeeeee ee Me(MMeMe8)8M8 (8eee%) ee MM8Me8 (88eM·eeee8) eee eeeee eeeeeeeeeeee ee 88% e-MeMMM (88 eeeee) eee (8M)-8,8,8-eeeeeeeeeeeeeeeeeee eeeeeeeeeeeeee eeeee (8 eeeee). Mee eeeee eee eeee eeee ee ee eee eee ee eee eeeee ee eeeeeeee eeee Me eeee. Me eee eee ee eee eeeeeeeee, eee eeeeeee eeeeee-eee eeeee eeeeee eeeeee. Meeee eeeeeeeeee eeee eeeeeee eee eeeeeeeeeee ee eeeeeeee, eee eeeee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee; eeeee: 88%.

References