Science of Synthesis

Suffert, J., Science of Synthesis, (2005) 26, 954.

The Neber rearrangement was discovered in 1926; it originally utilized O-tosyl oximes of benzyl ketones ‌265‌ (R1 = aryl; R2 = alkyl or aryl).[‌223‌–‌228‌] The probable mechanism involves the loss of 4-toluenesulfonic acid, mediated by deprotonation at the benzylic position, forming a nitrene and then an azirine.[‌229‌] Such azirines when refluxed in propan-2-ol with a catalytic amount of base give the isopropoxylated aziridines ‌266‌ in high yield. Azeotropic distillation of the aziridines in toluene, and acidic hydrolysis with hydrochlo­ric acid, affords amino ketones as the hydrochloride salts ‌267‌ (‌Scheme 120‌). When there are two potential sites for deprotonation, the direction taken favors the migration of the more electrophilic carbon atom to the nitrogen atom.[‌225‌]

‌Meeeee 888‌ Meeeeeeeee Meeeeeeee ee eee Meeee Meeeeeeeeeeee[‌888‌]

Mee M-eeeee eeeee eeee eee ee eeeeeeeeeeee eeeeeeee ee e eeeeeeeeeeeeeeeee, eeeee ee eeee “eeeeee” ee eeeeeeeeeeeeee eeee eeeeeeeeeee. Meee eeeeeeeeeeee ee eeee ee eee eeeeeeeee ee 88-eeeeeeeeeeeeeeeee (‌888‌); eeee, eeeeeeeee ee eee eeeeeeeeeeeeeeeee ee eeee­eeeeeeee ‌888‌ eeee eeeeeeeeeee eeeeeee eee eeeeeeeeee eeeeeeeeeee eeee ‌888‌, eeeee eeee eeeeeee eeee eeeeee eeeeeee ee eeeeeeee eeeeeeeee ee eeee eeeeeeeeeee eeeee eee eeeeeee ‌888‌ (88% eeeee). Meeeeeeee ee eeee eeeeeee eeee eeeeeee eee eeeeeeeeeeee eeee, eeeeeeee ee eee eeeeeeee ee eeeeee eeeeeeeee, eeeeee eee eeeee eeeeee ‌888‌ (88% eeeee) (‌Meeeee 888‌).[‌888‌] Meee eeeeeeeeee eee eeeee eeeeeee ee eeeee ee eeeeeee ee eeeeeeee eeee e Meeee-eeee eeeeeeeeeeeee eeeee e eeeeeeee eeeeeeee eeeeee eeee eeeeee eee eeeeeee eeeeeeeeeeee eeeeeeee eeeeee ee eee eeeeeeeee eeeeee eeee.

‌Meeeee 888‌ Meeeeeeee ee 8β-Meeee-8β-eeeeeee-88α-eeeee-8-ee-88-eee[‌888‌]

Meeeeeeeeeee Meeeeeeee

8β-Meeee-8β-eeeeeee-88α-eeeee-8-ee-88-eee (‌888‌):[‌888‌]

Meeeeeeeeee eeee ‌888‌ (88.88 e, 88.8 eeee) ee MMMM (888 eM) eee eeeeeee eeee ee e 88% eeeeeeeeee ee MeM ee eeeeeee eee (8.88 e), eee eeee eeeeeee ee ee eee 8 e. Mee eeee eee eeeeee eeee M8M (888 eM) eee eeeeeeeee eeee eeeeeee (MMMMMMM: eeeeeeeeee)/Me8M (8:8, 8.8 M). Mee eeeeeee eeeee eee eeeeee eeee eeee M8M, eeeee (MeMM8), eee eeeeeeeeeeee ee eeeeeee ee e eeeee eeee. Mee eeeeeee eee eeeeeeeeeeee (Me8M), eeeeeeeee eee eeeee eeeeeee (8.88 e), ee 888–888°M, eeeee eee eeeeeeee ee 888°M/8.8 Meee ee eeee eee eeeeeee ‌888‌; eeeee: 8.88 e (88%). M eeeeee eee eeeeeeeeeeeeee (MeMM); ee 888–888°M.

M eeee ee ‌888‌ (888 ee) ee MeMM (88 eM) eee eeeeeee eeee 8 M MMe (8 eM), eeeeee ee e eeeee eeee eee 8 e, eee eeeeee eeee M8M. Mee eeee eee eeeeee eeee Me8M, eeeeee, eee eeeeeeeeeee eeee eeee eeeee ee MeMM. M eeeeeeeeeee eeee eeeeee eee eeeeeeee, eeeeee eeee eeee M8M, eee eeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeee eeeee eeeeeeee; eeeee: 888 ee (88%). Meee eeeeeeee eeeeee ee 888°M, eeeeeeeeeeee, eee eeeeeeee ee 888–888°M. Mee eeeeeeeeeeeee eeee eee eeeeeeee ee eee eeeeeeee ee eeeee MMe ee ee Me8M eeee ee eee eeee eeee. Mee eeee eee eeeeeeeeeeee (MeMM/MeMMe); ee 888–888°M.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 88/8, 888.
• 8.Meeeee-Meee, (8888) 88M/8, 888.
• 8.Meeeee-Meee, (8888) 8/8e, 8888.
• 8.Meeeee-Meee, (8888) 8/8e, 8888.
• 8.Meeeee-Meee, (8888) M 88e8, 888.