Science of Synthesis

Constantieux, T.; Rodriguez, J., Science of Synthesis, (2005) 26, 441.

Unmodified 1,2-diols constitute the original substrates in the acid-promoted rearrangement to ketones and have been intensively studied for a long time. Since the first utilization of sulfuric201] and other Brønsted acids[‌207‌] as promoters, various efficient experimental modifications have been proposed over the years. For example, organic acids,[‌210‌] Lewis acids,[‌211‌–‌213‌] ammonium salts,[‌214‌] or solid acids[‌215‌] have had interesting effects on the rearrangement. Also of interest is the nondehydrative procedure[‌216‌] based on the utilization of a Lewis acid–trialkyl orthoester combined system involving catalytic amounts of tin(IV) chloride. Utilization of Brønsted acid ionic liquids as both catalyst and solvent has been reported for the first time in the preparation of pinacolone and benzopinacolone from the corresponding diols (‌Scheme 53‌).[‌217‌]

‌Meeeee 88‌ Meøeeeee Meee Meeee Meeeee Meeeeeee Meeeeee Meeeeeeeeeeee[‌888‌]

Meeeeeeeee eeeeeeeee eeeeeeeeeeee, eee eeeeeee ee eeeee- eee eeeeeeeeeeeeeeeee ee ee eeeee eeeeeeeeee eee ee eee eeee ee 8,8-eeeee eeee ee eeeeeee eee eeeeee ee eeeee eeeeeeee eeeeeeeee. Me eeeeeeeeeee eeeeeeeeeee eee eeee eeeeeeeee eee eee eeeeeeeee eeeeeeeeeeee ee eeeeeeeee eeeeeeeee eeeeeeeeee eeeeee ee eee eeeeeeeeeeee eeeeee.[‌888‌] Me eeee eeeeeeee eeee, eee eeeeeeeeeeeeeeee ee eee eeeeeeeeeeeee ee eee eeeeee ‌88‌ ee eeeeeeee ee eee eeeeeeeee eeeeeeeee ee e eeeeeeeeeee ee eee eeeeeeeeee eeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeee Meeeeeeeeeeee ee eee Meeeeeeeeeee Meeeee[‌888‌]

Meeeeee eeeeeeee eeeeee eee eeeeeeeeeee eee eeeeeeeee ee ee eeeeeeeeee eeeeeeeeeeeeeeee eee eeee ee eeeeee e eeee eeeeeeee eeeee ee eeee eeeee ee eeeee eeeee. Me eee eeeee eeee, eeee eee eeeee- eee eee eeeeeeeeeeeeeeeee eee ee eeeeeeeeee, eeeeeeee eee eeeeeeeeeeee ee eeeeeeeeee eeeeeee eeeeeeee ee e eeeeeeee eeeee. Meee eeeeeee eee eeee eeeeeeee eee eeeeeeeee eeeeeeeee[‌888‌] ee eeeee ee eee eeeeeeeeeeeeee eeeeeeeeeeeeeeee-eeeeeeee eeeeeee-eeee eeeee ee eeee 8-eeeeeeeeeee eeeeeee ‌88‌ (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Meeeeeeeeeee ee ee Meeeeeeeee Meeeee Meeeeeee ee e Meeeeeeeeee[‌888‌]

Meeeeeeeeeeee, 8,8-eeeeeee eeeeee eeee eeee eee eeeeee ee eeee eeeeeeeeeee eeeeeeeee, eeee ee eee eeeeeeeeeee ee eeeeeeeeeeee eeeeeee,[‌888‌] eee eee eee eeeeeeee eeeeeeeeeeeee ee eeeeeee eeeeeeeeee eeeeeee[8.8.8]eeeeeee[‌888‌,‌888‌] eeee eeeeeeeeeeeee eeeeee eeeeeee[8.8.8]eeeeeee.[‌888‌] Me eeee eeeee eeeeeeee eee ee eeeeeeee ee e eeeeeee eeeeeee eeeeeeeeeeeee ee eeee eee eeeeeee[8.8.8]eeeeeeeee eeeeeeeeeee ee e eeeeeeeeee eeeeeeee (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Meeeeeeeeeeee ee Meeeeee[8.8.8]eeeeeee ee Meeeeee[8.8.8]eeeeeee[‌888‌]

Meeeeeeee eee eeeee eeeeeeee ee e eeeeee eeeeee, ee eeee eeeeeeeeeeeee eee eeeeeeeeeeeeeeee, eee eeee eeeeee eeeeeeeeeeee eee eeeeeeee eee eee eeee eeeeeeeee ee eeee- eee eeee-eeeeeeee eeeee ee eeeeeeeeeee eeeeeee (‌Meeeee 88‌).[‌888‌–‌888‌]

‌Meeeee 88‌ Meeeeeeeeeeee ee Meeeeee eee Meeeeee Meeeeeeee eee eee Meeeeeeee Meeeeeeeeeee ee Meeee Meeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeeee

Meeeeee-Meee Meeeeeeeeeeee ee eee Meeeeeee ee Meeeeeeeeeeeeeeeeee Me Meee Meeeeee ‌88‌; Meeeeee Meeeeeeee:[‌888‌]

Me e eeeeeeeeee ee eee eeeeeeeeeeeee α-eeeeeeeeeeeeeeeee eeeeeeeeeeeeeeeeee (8.88 e, 8.88 eeee) ee MeMM (888 eM) eee eeeee, eeeee eeeee eeeeeeeeee, MMMM (8.88 eM, 88.88 eeee). Mee eeeeeeeee eeeeeee eee eeeeeee ee 88°M eee 88 eee eeee eeeeeeeeee eeee ee Me8M8M8 eee eeeeeeeeeeee ee eeeee. Mee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (eeeeee eee, MM8Me8/MeMM/M8M 88:88:8) ee eeeeee eee eeeeeeeeeeeee eeeeee; eeeee: 8.8 e (88%).

(8M)-8-(8-Meeeee-8M-eeeee-8-ee)-8-eeeeeeeeeeee-8-eee (‌88‌); Meeeeee Meeeeeeee:[‌888‌]

Me e eeee ee eee eeeeeeeeeeeee eeee (8M)-8-(8-eeeeee-8M-eeeee-8-ee)-8-eeeeeeeeeeeee-8,8-eeee (888 ee, 8.888 eeee) ee eeeee MM8Me8 (8.8 eM) eee eeeee Me8M (88 μM, 8.88 eeee) eee MeMe (88 μM, 8.88 eeee) ee 8°M eee 88 eee. Mee eeeeeeeeee ee eee eeeeeeee eee eeeeeeee ee eeeeee eee MMM (MeMMe/eeeeee 8:8; eeeeeeeeeeeeeeee: Me 8.88; eeee: Me 8.88), eee eeeeeeee eee eeeeee ee –88°M, eee 8.88 M Me8Me ee eeeeee (8.8 eM, 8.88 eeee) eee eeeee. Meeee 88 eee, eee eeeeeee eee eeeeee eeee ee MMMM8, eee eee eeeeeeee eeee eeeeeeeee eeee MeMMe (8 × 88 eM). Mee eeeeeeee eeeeeeee eeee eeeeee eeee M8M (88 eM) eee eeeee (88 eM), eeeee (MeMM8), eee eeeeeeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe 88:8) ee eeeeee eee eeeeeeeeee eeeeee ee e eeeeeeeee eee; eeeee: 88 ee (88%). Mee eeeeeeeeeeeee eeeeee eee eeeeeeeeee ee ee 88% ee eeeeee MMMM eeeeeeee [eMeMM/eeeeee 8:8 ee 8.8 eM·eee−8: eM (eeeee eeeeeeeeee) = 88.8 eee; eM (eeeee eeeeeeeeee) = 88.8 eee]; [α]88M –88 (e 8.88, MMMe8).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8, 888.
• 8.Meeeee-Meee, (8888) 8/8, 888.
• 8.Meeeee-Meee, (8888) 8/8, 88.
• 8.Meeeee-Meee, (8888) 8/8e, 888.
• 8.Meeeee-Meee, (8888) 8/8e, 8888.
• 8.Meeeee-Meee, (8888) 8/8e, 888.
• 8.Meeeee-Meee, (8888) 8/8e, 8888.
• 8.Meeeee-Meee, (8888) M 88-8, 8888.