Science of Synthesis

Wicha, J., Science of Synthesis, (2009) 48, 117.

Aldehydes and ketones with a sterically hindered carbonyl group, such as that located at the position α to a quaternary carbon atom or congested in a polycylic system, fail to afford the deoxygenation product under the Huang-Minlon modification conditions. Both stages of the deoxygenation process, namely hydrazone formation and hydrazone fragmentation, are arduous. Formation of an azine from the hydrazone and the parent carbonyl compound then becomes an important side process (‌Scheme 30‌). In principle, the azine may react with hydrazine to produce the hydrazone, but steric shielding may obstruct this reaction. The presence of water in the medium fosters formation of the azine through liberation of the parent ketone from the hydrazone.

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‌Meeee 8‌ Meeeeeee Meeeeeee ee eee Meeeeeeeeeeee ee Meeeeeeee eee Meeeeee eeeee eee Meeeee Meeeeeeeee[‌888‌,‌888‌–‌888‌]

Meeee	Meeeeeee ee Meeeee	Meeeeeeeee	Meeeeee	Meeee (%)	Mee
8		M8MMM8 (88 eeeee), Me (8 eeeee), 888°M, 88 e, eeee 888°M, 88 e		88e	[‌888‌]
8		M8MMM8 (eeeeee), Me (8 eeeee), eeeeee, 8 e		88e	[‌888‌]
8		M8MMM8 (88 eeeee) Me (88 eeeee), 888–888°M, 8.8 e, eeee 888–888°M, 8.8 e		88	[‌888‌]
8		M8MMM8 (eeeeee), MMM (ee. 888 eeeee), 888–888°M, 8 e, eeee 888–888°M, 88 e		88	[‌888‌]
8		M8MMM8 (eeeeee), Me (88 eeeee), 888°M, 88 e, eeee 888–888°M, 88 e		88	[‌888‌]
8		M8MMM8 (eeeeee), MeMM (ee. 88 eeeee), 888°M, 8 e, eeee 888°M, 8 e, eeee 888°M, 88 e		88e,e	[‌888‌]

e Mee eeeee eeeeeeeee eeeeeee eee ee-eeeeeeeeee.

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Meeeeeeeeeee Meeeeeeee

Meeeeeee-8β-ee Meeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeeee ee eeeeeeeee eee eee eeeeeeee eeee eeeeeeee ee eeeeeee. Me ee e eeeeee eeee eee eeeeee eeeeeeee eeeeeeee eee e eeeeeeee eeeee eeeeeeeeee.

Mee eeeeeeeeee eeee eeeeeee eee ee eee-eeeee eeeeeeeee eeeeeeeee eeeeeeeee eeee eeeeeeeeeee eeeeeeee. Me (88 e, 8.88 eee) ee eeeeeeeeeee eeeeeeeeee eeeeee (888 eM) eee eeeeee ee 888°M (eeeeee eeeeeeeeeee) eee eeeee M8MMM8 [eeeeeeee ee eeeeeeeee 888% M8MMM8•M8M (88 eM, 8.8 eee) eeee MeMM eeeeeee (88 e) eee 8 e] eee eeeeeeeee ee eeeee eee eeeeeee eeeeeeee eeeeee ee 888°M. Mee eeee eee eeeeee, (8β,8ξ,8ξ)-8,88-eeeeeeeeeeeee-8-ee eeeeeee (88 e, 8.88 eee) eee eeeee eeeeeee, eee eee eeee eee eeeeeeee eeeeeeeee. Mee eeeeeeeeeee eee eeee eeeeee ee 888°M ee eeeeeeeeee eee eeee ee eee M8MMM8 eee eee eeee eee eeeeeeee ee eeee eeee eee 88 e. Meeee eeeeeee, eee eeee eee eeeeeee eeee M8M eee eeeeeeeee eeee eeeeeee (MMMMMMM: eeeeeeeeee) ee eeee eee eeeee eeeeeee, eeeee eee ee-eeeeeeeeee. Mee eeeeeeeeee eeeeeee eeee eeeeeeee eee eeeeeeeeeeeeee (MMMe8/MeMM); eeeee: 88 e (88%).

8-Meeeee-8-(8,8,8-eeeeeeeeeeeeeeeeeeee)eeeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeeee ee eeeeeeeee eee eee eeeeeeee eeee eeeeeeee ee eeeeeee. Me ee e eeeeee eeee eee eeeeee eeeeeeee eeeeeeee eee e eeeeeeee eeeee eeeeeeeeee.

Meeeeeee eeeeee (8 eM) eee Me (888 ee) eeee eeeeee ee 888°M, eee ee eeeeee ee eeeee M8MMM8 (eeee eeeeee eeee MeMM) eee eeeeeeeee ee. Mee eeeeeee eee eeeeee eee 8,8,8-eeeeeeeee-8-(8-eeeee)eeeeeeeeeeeeee (888 ee) eee eeeee. Meeee eeeeeeeee eee 8 e, eee eeeeeee eee eeeeee eeee M8M eee eeeeeeeee eeee eeeeeeeee eeeee (ee 88–88°M). Mee eeeee eeeeeee eee eeeeeeee ee eeeeeeeeeee MMM; eeeee: 88 ee (88%).

(8M*)-Meeeeeee[8.8.8.8.8.8]eeeeeeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeeee ee eeeeeeeee eee eee eeeeeeee eeee eeeeeeee ee eeeeeee. Me ee e eeeeee eeee eee eeeeee eeeeeeee eeeeeeee eee e eeeeeeee eeeee eeeeeeeeee.

(8M*,8M*)-Meeeeeee[8.8.8.8.8.8]eeeeeeeee-8-eee (888 ee, 8.8 eeee) eee eeeee M8MMM8 (8.88 e, 88 eeee) eeee eeeee ee e eeeeeee ee eeeeeeeeee eeeeee (88 eM) eee Me (888 ee, 88 eeee) eeee eee eeeeeeee eeeee eeeee. Mee eeeeeee eee eeeeee ee 888°M eee 88 e (eeeee eee eeeeeeee eeeeee eee eeee eeeeeeee) eee eeee eee eeeeee M8MMM8 eee eee M8M eeee eeeeee eeee eeeeeeeee eee ee e eeeeee ee eeeee eeeee eee eeeeeeeeeee eee eeeeeeeee eeeeee ee 888–888°M. Meeeeee ee 888–888°M eee eeeeeeeee eee 88 e. Meeee eeeeeee, eee eeeeeee eee eeeeee eeee M8M (88 eM) eee eeeeeeeee eeee eeeeeee (8 × 88 eM). Mee eeeeeeeee eee eeeeee eeee eeeeeee (88 eM), eee eeeeeeee eeeeeee eeeeeee eee eeeeee eeee M8M (8 × 88 eM) eee eeeee (MeMM8), eee eee eeeeeee eee eeeeeeeeee. Mee eeeeeee eee eeeeeeeee ee eeeeeee eee eeeeeeee eeeeeee e eee ee eeeeee eee; eeeee: 888 ee (88%).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88e8, 888.