Science of Synthesis

Liu, L.; Wang, D.; Li, C. -J., Science of Synthesis: Stereoselective Synthesis, (2011) 2, 599.

Diastereoselective Mukaiyama aldol reaction of chiral aldehydes (e.g., ‌57‌) with silyl ketene acetals can be catalyzed by achiral Lewis acids. The configuration of the newly generated chiral center relies strongly upon the chiral center already existing in the starting chiral aldehyde. The reaction provides an efficient access to enantioenriched dihydroxy ketone derivatives (e.g., ‌58‌/‌59‌) in excellent diastereoselectivity (‌Scheme 25‌).

‌Meeeee 88‌ Meeeeeeeeeeeeeeeee Meeeeeeee Meeee Meeeeeee Meeee e Meeeee Meeeeeee[‌8‌]

Mee Meeee eeee eeeeeeeee eeeeeeeeeeeeeeeeee Meeeeeeee eeeee eeeeeeee ee e eeeeee eeeeeeee, eeeee eee ee eeeeeeee ee eeeeeeeeeeeeeee eeeeeeeeeeeeeeee eeeeeeeeeeee ee eee eeeeeeee ‌88‌, eee eeee eeeeeee ee eee eeeeeeeee ee eeeeeeeeeeeee (e.e., ‌88‌) (‌Meeeee 88‌).[‌88‌] Meee, e eeeeeeeee eeeee eeeee ee eeeee eeeeeeee ee eeeee eeeeeeeee eee eeee eeeeeeeee eee eee eeeeeeeeee ee eeeeee-eeeeeeeeeeeeee eeeeeee ee eeee eee eeeeeeee eeeee.

‌Meeeee 88‌ Meeeeeeee ee e Meeeeeeeeeee Meeeeeeeee eee Meeeeeeeeeeeeeeeee Meeeeeeee Meeee Meeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

(8M,8M,8M)-8-[(8-Meeeeeeeeeeee)eee]-8-eeeeeee-8,8,8,8-eeeeeeeeeeeeeeee-8-eee (‌88‌); Meeeeee Meeeeeeee:[‌8‌]

MM8•MMe8 (88 µM, 8.88 eeee) eee eeeee eeeeeeee ee e 8.8 M eeee ee 8,8-eeeeeeeeeee-8-ee-8-ee eeeeeeeeeeeeee eeeee (88 µM, 8.88 eeee), eee eeeeeeee eeee-‌88‌ (88 ee, 8.88 eeee) ee MM8Me8 ee −88 °M. Mee eeeeeeee eee eeeeeee ee eeeeeee eee 88 eee, eeeeeeee ee eeeeeeee ee ee eeeeeeeeee eeeeee ee eee. ee MeMMM8, eee eeee eeeeee ee eeeeeee eeeeeeeeeee. Mee eeeeeee eee eeeeeee eeee MM8Me8 eee eeeeee eeee eee. ee MeMMM8. Mee eeeeeee eeeeeeee eeee eeeeeeeee eeee eeee MM8Me8. Mee eeeeeeee eeeeeee eeeeee eeee eeeee (Me8MM8), eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:8) ee eeee eee eeeeeee ee e eeeeeeeee eee; eeeee: 888 ee (88%); [α]M88 −88.8 (e 8.8, MM8Me8). Mee eeeee ee eeeeeeeeeeeee eee eeeeeeeeee ee 8M MMM eeeeeeeeeeee ee eee eeeeeeeeee eeeeeee ee 88:8.

8-M-Meeeee-8,8-eee-M-(eeeeeeeeeeeeeeeee)-α-e-eeeeeeeeeeee (‌88‌); Meeeeee Meeeeeeee:[‌88‌]

Me ee eeeee-eeeeeeeeee eeeeeeee, e 88-eM eeeee-eeeee eeeee eee eeeeeee eeee MeMe8•8MMM (888 ee, 8.88 eeee) eee e eeeeeeee eeeeeee eee. Mee eeeee eee eeeeeee eeee eee eeeeeeee eee eeeeee eeeee eeeee, MM8Me8 (8.8 eM) eee eeeee, eee eee eeee eee eeeeee ee −88 °M. Meee, {[(M)-8-(eeeeeeeeeeeeeee)eeeee]eee}eeeeee)eeeeeee (888 ee, 8.88 eeee) eee eeeee eeeeeeee eeeeeeee ee e eeee ee (8M,8M)-8-eeeeeee-8,8-eee(eeeeeeeeeeeeeeeeee)eeeeeee (888 ee, 8.88 eeee) ee MM8Me8 (8.8 eM). Mee eeeeeeeee eeeee-eee eeee eee eeeeeee ee −88 °M eee 8 e eeeeee eeeee eeeeeee ee eeeeeeeee eeee ee −88 °M eeee eee eeeeee ee 8 e. Mee eeeeeee eee eeee eeeeeeeee ee eee eeeeeeee ee eee. ee MM8Me (888 eM), eeeeeeeee eeee MeMMe (8 × 88 eM), eeeeee eeee 88% MeMMM8 (888 eM) eee eeeee (888 eM), eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeee 8M MMM eeeeeeee eeeeeeeee eeeeeeee eeeeeeeeee eeee e >88:8 eeeeeee ee eeeeee/eeeeeee eeeeeee eeeeeeeeeeeee ee eeee ee eeee eeeee eeeeee eeee eeeeeeee. Meeee eeeeeeeeeeeeee (Me8M/eeeeeee 8:8 eeee 8% MeMM8) eeeeeeee eee eeeeeee ee e eeeee, eeeeeeeee eee; eeeee: 888 ee (88%); 88% ee.

References