Science of Synthesis

MacMillan, D. W. C.; Watson, A. J. B., Science of Synthesis: Asymmetric Organocatalysis, (2012) 1, 313.

Intramolecular applications of the iminium-mediated Diels–Alder reaction have focused heavily on the use of aldehyde-based substrates.[‌35‌–‌38‌] These transformations enable the direct enantio- and diastereoselective preparation of bi- and tricyclic cycloadducts from suitably disposed dienals. Levels of functionality vary from examples which construct relatively unsubstituted carbocycles to those that forge highly functionalized tricycles that constitute the core of natural products.

Meeeeeeee eeeeeeeeee eee eeeeeeeee eeee eeeeeee eee eeeeeeeeeeeeeee, eeeeeeeee eeeeee eee eeeeeeeeeeeeee eeee eee eeeeee eeeeeeeee eee eeeeeeee eeeeee ee eeee eeeeeeeeeee ee eeeee (e.e., −88 °M) eeeee eeeeeeee eeeeeeeeeee ee eee eeeeeeee eeeeeeee. Meeeeee- eee eeeeeeeeeeeeeeeeeeeeee eee eeeeeeeee eeee eeee eeee eeeeee eeeeeee eeee eeeeeeee ee eeeeeeeee (‌Meeee 8‌). Meeeeeee eee eeeeee eeeeeeee ee eee eeeeeeee ee eee eeeeeeeeeeeee eeeeeee (e.e., ‌8‌), eeeeeeee eee eeeeeeeee eeee eeeeee eeeeeeeeeee (‌Meeeee 8‌).

‌Meeee 8‌ Meeeeeeeeeeeeeee Meeeeeeeeeeeee Meeee–Meeee Meeeeeeee[‌88‌–‌88‌]

Meeee	Meeeeeeee	Meeeeeeeee	Meeeeee	Meeee (eeee/eee)	ee (%)	Meeee (%)	Mee
8		‌8‌ (8.8 eeeee), MMeM8 (8.8 eeeee), M8M (8.8 eeeee), MeMM (8.88 M), −88 °M		>88:8	88	88	[‌88‌]
8		‌8‌ (8.8 eeeee), MMeM8 (8.8 eeeee), M8M (8.8 eeeee), MeMM (8.88 M), −88 °M		>88:8	88	88	[‌88‌]
8		‌8‌ (8.8 eeeee), MMeM8 (8.8 eeeee), M8M (8.8 eeeee), MeMM (8.88 M), −88 °M		88:8	88	88	[‌88‌]
8		‌8‌ (8.88 eeeee), MeMM/ M8M (88:8; 8.88 M), ee		eee eeee	–e	88	[‌88‌]
8		eee-‌8‌ (8.88 eeeee), MeMM/M8M (88:8; 8.88 M), ee		88:8	–e	88	[‌88‌]
8		eee-‌8‌ (8.8 eeeee), MMM (8.8 eeeee), M8M (88 eeeee), MeMM (8.88 M), −88 °M		eeee eeee	88	88e	[‌88‌]
8		‌8‌ (8.88 eeeee), 8.8 M ee MMe (8.8 eeeee), MeMM (8.88 M), ee		>88:8	88	88	[‌88‌]

e Meeeeee ee eee eeeeeeee; eeeeeeeeeee eeeeeeee eeeeeeee eee eeeeeeee.

e Meeeeee eeeee eee eee eeeee. Meeeeeee eeeeeeee ee eee-eee MeM8 eeeeeeeee ee eee eeeeeeeeeeeee eeeeeee.

‌Meeeee 8‌ Meeeeeeee ee Meeeeee eee Meeeeeeeeeeee ee Meeeeeeeeeee Meeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

(8eM,8M,8M,8eM)-8-Meeeee-8,8,8e,8,8,8e-eeeeeeeeeeeeeeeeeeeeee-8-eeeeeeeeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeeeeeeeeee eeeeeeeee eeeeeeeeee eeee (88–88%) eee eeeee eeeeeeeeeee ee eeeeeeeee eeee e eeeee ee eeeeeee eee eeeeeeeee eeeeeeeeee eee ee eeeeeeeee eeeeeeeeeee ee eee eeeeeee.

Me e eeeeeee ee (8M,8M)-8-eeeeee-8-eeee-eeeee-8-eeeeeeeeeeeeeeeeee-8-eee (‌8‌; 88.8 ee, 8.888 eeee, 8.8 eeeee) eee MMeM8 (88%; 8.8 ee, 8.888 eeee, 8.8 eeeee) ee MeMM/M8M (88:8; 8.8 eM) [eeeeeeee ee 8.8 ee (8.88 eeee, 8.8 eeeee) ee M8M] eee eeeee (M)-8-{[(8M,8M)-8-eeeeeeeeeee-8,8-eeeeee]eee}eee-8-eeee (88.8 ee, 8.88 eeee, 8 eeeee) ee e eeee ee MeMM (8.8 eM; 8.88 M eeeeeee). Mee eeeeeeeee eeeeeee eee eeeeeee ee −88 °M eee 8 e eeeeee ee eee eeeeee ee ee eee eeeeeeee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (MeMMe/eeeeee 88:88 ee 88:88) ee eeeeee eee eeeee eeeeeeee; eeeee: 88.8 ee (88%); 88% ee. Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee eeeee eeeeeeeeee eeee eee eeeeeeeeeeeee eeeeee eeeeeee eeee (8M,8M)-eeeeeee-8,8-eeee. Me eeeeeee eeee eeeee eee eeee eeeeeee; eeeeeee, e eeeeeee eeeeeeee eee eeeeeeeeeee eeeee (8M,8M)-eeeeeee-8,8-eeee eee MeMM ee MM8Me8 ee ee, eeee eee eeeeeeeeeeee eeeeee eeee eeeeeeeeee ee MM eeeeeeee (β-MM eeeeee, 88 °M/88 eee, 8 °M · eee−8 eeee ee 888 °M/88 eee).

(8M,8eM,8M,8M,88M,88eM,M)-88-(Meeeeeeee)-8-[eeeeeeee(eeeeee)eeeee]-8-eeeeee-8,8,8e,8,8,8,88,88,88,88e-eeeeeeeee-8,88-eeeeeeeeee[88]eeeeeeee-8-eeeeeeeeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌88‌]

Me (M)-8-eeeeee-8,8,8-eeeeeeeeeeeeeeeeeeeee-8-eee eeeeeeeeeeee eeee eeee (‌8‌•MMe; 8.8 ee, 8.888 eeee, 8.88 eeeee) ee MeMM/M8M (88:8; 8 eM) eee eeeee (M)-8-{(8M,8M,8M,8M,M)-8-(eeeeeeeee)-8-[eeeeeeee(eeeeee)eeeee]-8-[(M)-8-eeeeeeeeee-8,8-eeeeee]-8,8,8,8,8,8-eeeeeeeeeeeeeee-8-ee}eeeeeeee (88.8 ee, 8.88 eeee, 8 eeeee). Mee eeeeeeeee eeeeeee eee eeeeeee ee ee eee 88 e eeeeee eeeee eeeeeee eeee Me8M (8 eM) eee eeeeee eeee M8M (8 eM) eee eeeee (8 eM). Mee eeeeeee eeeeeee eee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeee e eeeeeee, eeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (MM8Me8) ee eeeeee eee eeeee eeeeeeee (eee-eeeeee eeee); eeeee: 8.8 ee (88%, ee eeeeeeee). (Meee: e 88% eeeee ee eeeeeeee ee eee eeeeeeeeee eeeeeeeeeee.)

(8eM,8M,8M,8eM)-8-(Meeeeeeeeeeeeee)-8,8,8e,8,8,8e-eeeeeeeee-8M-eeeeee-8-eeeeeeeeeeee (‌Meeee 8‌, Meeee 8); Meeeeee Meeeeeeee:[‌88‌]

Me (8M,8M)-8-eeeeee-8-eeee-eeeee-8-eeeeeeeeeeeeeeeeee-8-eee (‌8‌; 888 ee, 8.88 eeee, 8.88 eeeee) ee MeMM (88 eM) ee ee eee eeeee 8 M ee MMe (8.8 eM, 8.8 eeeee). Mee eeeeeee eee eeeeeee eee 8 eee eeeeee eeeeeeee ee (8M,8M,8M)-88-(eeeeeeeee)eeeeee-8,8,8-eeeeeee (88 ee%; 8.88 e, 8.88 eeee, 8 eeeee) ee e eeee ee MeMM (88 eM; 8.88 M eeeeeee). Mee eeeeeeeee eeeeeee eee eeeeeee eee 88 e eeeeee eeeee eeeeeee eeee Me8M (888 eM). Mee eeeeeee eee eeee eeeeee eeee M8M (88 eM) eee eeeee (88 eM). Mee eeeeeee eeeee eee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeee e eeeeeee, eeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (MeMMe/eeeeee 8:88) ee eeeeee eee eeeee eeeeeeee; eeeee: 8.88 e (88% eeeeeeee; 8.88 e eeeeeeeeee ee ee 88%). Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee eeeee eeeeeeeee ee eee eeeeeeeeeeeee eeeeeee ee eeeeeeeee ee eee eeeeeeeee eeeeeeeee.

[(8eM,8M,8M,8eM)-8-(Meeeeeeeeeeeeee)-8,8,8e,8,8,8e-eeeeeeeee-8M-eeeee-8-ee]eeeeeeee (‌8‌):[‌88‌]

(8eM,8M,8M,8eM)-8-(Meeeeeeeeeeeeee)-8,8,8e,8,8,8e-eeeeeeeee-8M-eeeeee-8-eeeeeeeeeeee (‌Meeee 8‌, eeeee 8; 8.8 ee, 8.888 eeee, 8 eeeee) ee MeMM (8 eM) ee ee eee eeeeeee eeee eeeeee MeMM8 (eeeeeeee eee eeeeeeee). Mee eeeeeeeee eeeeeee eee eeeeeee eee 8 e eeeeee eeeee eeeeeeee eeee 8 ee% ee eeeeee eeee (8 eM). Mee eeeeeee eee eeee eeeeeeeee eeee Me8M (8 × 8 eM) eee eee eeeeeee eeeeeeee eeee eeeeee eeee eeeee (8 eM), eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee; eeeee: 8.8 ee (888%); 88% ee. Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee ee MMMM eeeeeeee [MM eeeeee, eMeMM/eeeeee 8:88, 888 ee, 8.8 eM · eee−8; eM (eeeee) = 88.8 eee, eM (eeeee) = 88.8 eee].

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