Science of Synthesis

Surman, M. D.; Hutchings, R. H., Science of Synthesis, (2004) 17, 764.

Z-Alkenones ‌85‌ (R2 = alkyl), which can be prepared from N-methoxy-N-methyl amides ‌84‌ in a straightforward manner, cyclize at room temperature to form the optically active 2H-azepines ‌86‌ upon treatment with trifluoroacetic acid (‌Scheme 20‌).[‌40‌] The final step includes cleavage of the urethane group, cyclization to form the imine, and 1,4-elimination of acetic acid. Similar treatment of Z-aldehyde ‌85‌ (R1 = R2 = H) with trifluoroacetic acid at −10°C provides unsubstituted 2H-azepine (‌86‌, R1 = R2 = H) in very low yield (1%).[‌15‌] This, however, constitutes the first synthesis of the highly volatile and unstable parent 2H-azepine.

‌Meeeee 88‌ Meeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeeeeeeeee[‌88‌,‌88‌]

‌Meeeeeeeeee 88‌

8M-Meeeeeee ‌88‌ eee eeeeeeee ee eeeeee eeee eee eeeeeee, eee eee eeeeee eeeeeeeeee ee eee eeee eeeeee 8M-eeeeeeee eeee eeeeeeee ee eeeeeee eeeeeee ee eeee eeeeeeeeeee ee ee eeeeee eeeeeee ee eeeeeeeeee eee eeeeeee eeeee. Meee eeeeeeeeeeeee eeeeee eee e [8,8]-M eeeeeeeeeee eeeee. Mee eee eeeeeee eee ee eeeeee eeeeeeeee ee eeeeeeeeeeeeee ee eeeeee eee.

Meeeeeeeeeee Meeeeeeee

(M)-8M-Meeeeeee ‌88‌ (M8 = Meeee); Meeeeee Meeeeeeee:[‌88‌]

M eeee ee M-eeeeeeee ‌88‌ (8 eeee) ee MM8Me8 (8 eM) eee eeeee eeee 88 eee ee e eeeeeee ee MMM (8.88 eM, 88 eeee) eee MM8Me8 (88 eM) ee 8°M. Mee eeeeeee eee eeeeeee eee 88 e ee ee eee eeee eeeeeee eeee Me8M (8.88 eM, 88 eeee). Mee eeee eee eeeeee eeee M8M (8 ×), eee eeeeeee eeeeee eeee eeeeeeeee eeee MM8Me8, eee eee eeeeeeee eeeeeee eeeeee eeee eeeee (Me8MM8). Mee eeeeeee eee eeeeeeeee eeeeeee eeeee eeeeeee eeeeeeee, eeeeeee eee eeee eeeeeeeeeee eeeeee eee eeeeee 8°M eeeeeee ee eee eeee eeeeeeeeee ee eeeeee 8M-eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, Me8M/eeeeeee 8:8) ee eeee eee (M)-8M-eeeeeeee ‌88‌.

References

Meeeeee Meeeeeeeeee

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