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Please login or sign up for a free trial to access the full content. Variation 4: Alkylation and Michael Addition of Enantiomerically Pure Hydrazone Enolates

DOI: 10.1055/sos-SD-025-00237

Göttlich, R.Science of Synthesis, (200725363.

A variety of chiral reagents can be used to achieve enantioselective reactions at the α-positions of aldehydes.[‌75‌,‌76‌] Amongst these, the hydrazones derived from (S)-1-amino-2-(methoxymethyl)pyrrolidine [SAMP, (S)-11] and (R)-1-amino-2-(methoxymethyl)pyrrolidine [RAMP, (R)-11], developed by Enders in 1976, are the most successful and reliable.[‌77‌‌79‌] One reason for this is the simple and rapid access to the two required enantiomeric hydrazines from D-glutamic acid and L-proline, respectively (Scheme 14).[‌80‌,‌81‌]

Meeeee 88 Meeeee ee MMMM eee MMMM[‌88‌,‌88‌,‌88‌]

Meeee eeeeee eeeeee eee eeeeeee eeeeeeeeee ee eeeeee eee eeeeeeeee eeee eee eeeeeeeeeeeee eeeeeeee eee eeeeeeee eee eeeee eeee ee eeeeee ee eee eeeeeeee ee eeeeeeeeee eeeeeeeeeeee. Meeeeeeeeeeee ee eee eeeeeeeee eeeeeeeeee eeee eeeeeee eeeeeeeeeeeeeeee eeeee ee ee eeeeeeeeee ee eeeee eee eeeeeee eeeeee ee eeeee eeee eee eee eeeeeeeeee eeeeeee eeeeeeee eeee eee eee eeeeeee eeeee (Meeeee 88).[‌88‌] Mee eeeeeeeeeeeee eeeeee eee MM=MM8 eeee ee eeee eeeeeee ee M, ee ee eee eeee eeee eeeeeeeeeeeee ee eeeee eeeeeeeeee.[‌88‌] Mee eeeeeeeeee eeeee eeeeee eeee eee eeee eeee ee eee eeeeeee eeeeee (eeeeeee-eeeeeeeee eeeeee[‌88‌]), eeeee eee-eeeeeeeeeee eee eeeeeee eeeee (Meeeee 88). Me eeee eeeeeeeeeee ee eee eeeeeeeee eee eeeeeee eeeeeeeee, eee eeeeeee eeeeeeeeeeeeeee eee ee eeeeeeee eeeeeee ee eeeeeeeeeee eeeeee ee eee eeeeeeeee. Mee eeeeeeeeeeeeee eeeeee eeeeeeee ee eeeee eeeeeeeeee eeeeeeeee eee eeeeeeee eeee eeee 88% ee.[‌88‌]

Meeeee 88 Meeeeeee Meeeeeeee ee e Meeeeeeeeeeeeeeeee Meeeeeeeee[‌88‌]

Mee eeee eeee eeee eeeeee ee eeeeee eeeeeeee eee eeee eee eeeeeeeeeeeeee eeeeeee ee eee eeeeeeee eee ee eeeeeeeee eeeee ee eee ee eee eeee eeeeee eeeeeeeee ee eeeeeeeeee eeeeeeeee. Meee eeeeeeee eee eeeee ee Meeeee 88.[‌88‌,‌88‌] Mee eeeeeeeeee eeeee ee eeeeeeeee eeeeeeeeeeeeeeeeee eeee eeeeeeee 88, ee eeeeeeeeee ee MMM. Meeeeee, eee eeeeeeeeeeee eeeeeeee eeeeeeee eee eee eeeeeeeee eeeeeeeee 88 ee eeeee eeeee eeeeeee eee eeeeee eeeee eeee eeeee eeeeeee eeeeeeeeeee (88%[‌88‌]).

Meeeee 88 Meeeeeeeee Meeeeeeeee ee Meeeeeeeeeee Meeeeeee MMMM Meeeeeeeee eee Meeeeeeeee ee eee Meeeee Meeeeeeee[‌88‌]

Meeeeeeeeee 88

M8 M8M Meeee (%) ee 88 ee (%) ee 88 Mee
Me MeMe 88 88 [‌88‌]
Me MeM 88 88 [‌88‌]
Me MeM 88 e [‌88‌]
eMe MeM 88 88 [‌88‌]
(MM8)8Me MeM 88 88 [‌88‌]
Me Me8MM8 88 88 [‌88‌]

e Mee eeeeeeee.

Meeeeee eee MMMM eeeeeeeee eeeeee eeeeeee eeeee eeeeeeeee eeeeee eeeeeee ee eeee eeeeeeeeeeeeee eeeeeeee, eeeee eeeeeeeeeeeeee eeeeeeee, eee eeee eeeeee, eee eeeeeeee ee eee eeeeeeeeeeee ee eeeeeeeeee eeeeee eeeeeee.[‌88‌] Me eeeeeee ee eee eeeeeeeeee ee eee MMMM eeeeeeeee ee 8-eeeeeeeeeeeeee, eeeee eeeee 8-eeeeee-8-eeeeeeeeee-8-eeee ee 88% eeeee.

Mee eeeeeeeeeeee MMMM eee MMMM eeeeeeeeee eee eeeeeeee eeeeeeee eee eeeeeeeeeeeeeeee α-eeeeeeeeee eee eee eeeeee eeee ee eeeeeeeee ee eeeeeee eeeeeeee.[‌88‌,‌88‌] Meeeeeeeeee, eeeee eeeeeeee eee eeee ee eeee ee eeeeeeeeeeee ee Meeeeee eeeeeeeee (Meeeee 88).[‌88‌]

Meeeee 88 Meeeeee Meeeeeeee ee e Meeeeeeeeeee Meeeeeee MMMM Meeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Meeeee Meeeeeeee 88; Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeeeeee, eeeeeeeee, ee eeee eeeeeeeeee ee eeeeeeeeeee eee ee eeeee.

M8MM8MMM (8.88 eeeee) eee eeeee eeeeeeee ee eeee MMMM (8.88 eeeee) ee 8°M eeee eeeeeeee. Mee eeeeeee eee eeeeeee ee 88°M eee 88e eeee eeeeeeeee eeee MM8Me8. Mee eeeeeeee eeeeeee eeeeee eeee eeeee (Me8MM8) eee eeeeeeeeeeee ee eeee eee eeee eeeeeeeee 88.

Meeeeeeeeeeee, e eeee ee M8MM8MMM (8.88 eeeee) ee eeeeeee (88eM eee 88eeee) (MMMMMMM: eeeeeeeeee) eee eeeeeee eeee MMMM (8.88 eeeee) eee eee eeeeeee eee eeeeeeee, eeeee eee M8M eeee eeeeee eee eeeeeee ee eeeee e MeeeMeeee eeee: ee eeee eeeee, eeee eeee eeeeeee eeee. Mee eeee eee eeee eeeee (MeMM8) eee eeeeeeeeeeee ee eeee e eeeeee eeee eeeeeee eeee eeeee ee eeeeeee eeeeeeee ee eeeeeeeeeeee.

Mee eeeeeeeee 88 (8.88 eeeee) eee eeeee ee e 8.8M eeee ee MMM (8.88 eeeee) ee MMM ee 8°M. Mee eeee eeeeeeeeeee eeeeee eeeeee eee ee eeee eeeee eee eeeeeeeee eeeeeeeee eeeeeeeeeeee. Mee eeeeeeeeeeeee eee eeeeeeee ee 88e, eeeee eeeee eee eeee eee eeeeee ee 88°M eee eeeeeee ee eeee eeeeeeee ee e eeee ee M8M (8.88 eeeee) ee MMM eeee eeeeeeee eeeeeeee. Mee eeeeeee eee eeee eeeeeee eee 8e ee 88°M, eeeeeee ee eeee ee ee, eee eeeeee eeee Me8M/M8M (8:8). Mee eeeeee eeee eeeeeeeee eee eee eeeeeee eeeee eee eeeeeeeee eeee Me8M (8×). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8) eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeee eeeeeeeee eeeeeeeee 88, eeeee eeeee ee eeeeeee eeeeeeee ee eeeeee eeeeeeeeeeee ee eeeeee eeeeeeeeeeeeee.

M eeeeeee ee eee eeeeeeeee MMMM eeeeeeeee 88 (88eeee) eee MeM (8.8eM) eee eeeeeeee eee 888e (MMM eeeeeeeeee). Meeeee MeM eee eeeeeee eeeee e eeeeeee eeeeeeee eee eee eeeeeeeee eeeeeeeeeee eeeeee eee eeeeeeeee ee 8M ee MMe (88eM). Mee eeee eee eeeeeee eee 8eee, eeee eeeeeee (888eM) eee eeeee eee eeeeeeee eee eeeeeeeee (eeee eeeeeeeeee eeeeeee) eee 88eee. Mee eeeeee eeee eeeeeeeee eee eee eeeeeee eeeee eee eeeeee eeee M8M (8×), eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeeeeee 88, eeeee eee eeeeeeee ee eeeeeeeeeeee.