Science of Synthesis

Fringuelli, F.; Piermatti, O.; Pizzo, F.; Vaccaro, L., Science of Synthesis, (2010) 47, 682.

A number of chiral auxiliary groups (‌301‌–‌307‌) and the chiral dienophiles ‌308‌ and ‌309‌ are illustrated in ‌Scheme 118‌. Because of their chemical versatility, α,β-unsaturated carbonyl compounds are almost exclusively used as the dienophile partners with dienes derived from these auxiliaries, and some applications of such cycloadditions are depicted in ‌Scheme 119‌. Thus, diethylaluminum chloride or dimethylaluminum chloride promote the rapid cycloaddition of the carboxamides ‌310‌ onto butadienes in dichloromethane at −100°C with a good level of asymmetric induction. The removal of the oxazolidin-2-one auxiliary (structure ‌301‌, see ‌Scheme 118‌) from the adducts ‌311‌ proceeds in excellent yields when lithium phenylmethanolate is employed as the reagent, and gives the corresponding benzyl ethers.[‌448‌] The N-acryloylsultam ‌312‌ reacts with highly reactive dienes (such as cyclopentadiene) as well as with poorly reactive open-chain butadienes in the presence of diethylaluminum chloride with high chiral efficiency. Cyclohex-3-enecarboxylic acid and cyclohex-3-enylmethanol are then easily obtained by the removal of the auxiliary (structure ‌302‌, see ‌Scheme 118‌) from the adduct ‌313‌ formed when buta-1,3-diene is used.[‌449‌]

Meeee–Meeee eeeeeeeeeeeeee ee eee eeeeeeeeeee ‌888‌ eeee 8,8-eeeeeeeeeeee-8,8-eeeee eee eeeeeeee, eeeeeeee ee eeeeeeeeeeeeeee eeeeeeee ee eeeeeeeeeeeeeeee eeeeeeee ee eeeeeeeeeeeeeee, eeeeeee ee eeeeeeeeeeee eeeeeee 8 eee 88°M eeee eeee eeeeeeeeeeeeeee eeeeeeeeeee. Meeeee (eeee-M)- ee (eeee-M)-eeeeeeeeeeeee ee eee eeeeeeeeeeeeeeeeeeee ‌888‌ (M8 = M8 = Me) eee eeeeeeee eeeeeeeee eeee eee eeeeeeeee ee eee eeeeeeeeeee eee eee Meeee eeee eeee.[‌888‌] Meee, ee eee eeee ee e eeeeeeeeeeeee eeeeeee eee eeeeeeeeee ‌888‌ (M8 = MM8Me; eeee ‌888‌, ‌Meeeee 888‌) eee 8,8-eeeeeeeeeeee-8,8-eeeee, eee Meeee eeee eeeeeeee, eeeeeeeeeeeeeee eeeeeeee, eeeeeeee eee eeeeeeeee ee eee eeeeeee (eeee-M)-‌888‌ (M8 = M8 = Me) eee (eeee-M)-‌888‌ (M8 = M8 = Me) ee e eeeee ee 8:88, eeeeeee eeee eeeeeeee(MM) eeeeeeee ee eee eeeeeeee eee eeeeeeeeeeee eeeee ee eeeeeee eee eeeeeeee, eee eeee eee eeeeeeeeee ‌888‌ (M8 = MMe8MM; eeee ‌888‌, ‌Meeeee 888‌) ee eeee eeee eee eeee eeeee eee eeeee eeee eeeeeeeeeeeeeee eeeeeeee (88:8) ee eeeeee eeeeeeeee eeee eeee eeeeeeee eeee eeeeeeee(MM) eeeeeeee ee eeeeeeee (88:8).[‌888‌]

‌Meeeee 888‌ Meeeee Meeeeeeeeee eee Meeeee Meeeeeee Meeeee

Mee eeeeeeeeee ee ee 8-eeeeeeeeeeeee eeeeee ‌888‌ ee e eeeeee eeeeeeeee ee eeee eeeeeeeeee ee eeeeeeeeee Meeee–Meeee eeeeeeeee.[‌888‌–‌888‌] Mee eeeeeeeeeee eeeeee ee eee eeeeeeeeeee ee eeeeeeeeeeeeee eeeeeee eee eeeeeeeeeee ‌888‌ eee eeeeeeeeeeeeeee ee eeeeeeeeee; eee eeeeeee, eeeeeeeee eeeeeeeee ee eee eeeeeeeeeee eee-eeeeee ‌888‌ ee eeeeeeee eeee eee eeeeeeeeeee M8 ee eeeeeeee, ee ee eee-eeeeee eeeeeee eee eeeeeeeeeee eeeeeee eeee M8 ee eeeeee eeeeeeee ee eeeeee. Meeeeee, eeee M8 ee eeeeeeee, eee eeeeeeeeeeeeeeeeeeee ee eeeeeee eeeeeeee ee eeeee ee eee eeeeeeeeeeeee eeee-eeeeee.[‌888‌] Mee eeeeeeee ‌888‌ (eeeeeeeee ee eeeeeeeee ‌888‌, eee ‌Meeeee 888‌) eeeeeeee eeeeeeeee eeeeeeeee- eee eeeeeeeeeeee ee eeeee eeeeeeeeeee eeeeeeeee Meeee–Meeee eeeeeeeee eeee e eeeeeee ee eeeeeeeeeee eee eeeeeeeeeeeee eeeeee. Me eee eee ee eee eeeeeeee eee eeeeee eeeeeeeee ee eeeeee eeeeeee eeee eee eeeeeee ‌888‌ ee eeeeeeeeee eee eee ee eeeeee.[‌888‌] Mee (M)-eeeeeeeeeeee eeee ‌888‌ eeeeeeee ee eeeeeeeee eeeeee eeeeeeeee,[‌888‌,‌888‌] eee eee eeeeeeeeeeeee ee eeee eeeee eeeeee eee eeeeeeee eeeeee eee eeeeeeeeee Meeee–Meeee eeeeeeeee eeee eeeeeeeeeeeeeee eee eeee eeeeee eeee e eeeeeee ee Meeee eeeee.[‌888‌] Mee eeeeeeeeeeeeee ee eee eeeeeeee ‌888‌ eeee eeeeeeee ee eeeeeeeee eee eeee eeeeeeeeeeeeee eee eeee eee eeeeeeee eeeeeee ‌888‌ ee eeee eeeeee eee eeee eeee eeeeeeeeeeeeee eeeeeeee. Meee eeee eeeeee eee eeeeeeeeeee ee eeeeeeeeeeeeeeee eeee eeeeeeeeeee-8-eeeeeeeeee eeeee.[‌888‌]

Meeeeeeee 8-(M)-eeeeeeeeeeeeeeeeee-8-eee ‌888‌ eee (M)-eeeeeee (‌888‌) eee eeeeee eeee ee eeeeeeeee eeeeeeeeeee-eeeeeeeee eeeeeeeeeeeeee eeee eee eeee ee eeeeee eeeeeeee eeeeee eee eee eeeeeeeee ee eeeeeeeee eeeeeeeee eeeeeeeee; eeeeeeee eee eee-eee-eeeeeeeeeeee,[‌888‌] α-eeeeeeee,[‌888‌] eee M-eeeeeeee.[‌888‌] Mee eeeeeeeeeeeeee ee eeeee eeeeee eeeeeeeeeee eeee eeeeeeeee ee 8-(eeee-eeeeeeeeeeeeeeeeeee)-8-eeeeeeeeee-8,8-eeeee eee eeeeeeeee ee eeeeeeee eeeeeeeeeee ee eeeeeeeeeeeee eeeeeeeeee, eeeeeeeeeeee, ee eeee eeeeeeeeeee eee eeeeeee eee eeeeeeeeeee eeeeeeee eeeeee ‌888‌ eee ‌888‌ ee eeee eeeeee.

‌Meeeee 888‌ Meeeeeeee ee Meeeeeeee Meeeee Meeeeeeeeeee eeee Meeeee Meeeeeeeeee[‌888‌–‌888‌,‌888‌,‌888‌,‌888‌–‌888‌]

‌Meeeeeeeeee 888‌

Mee eeeeeee ee eee eeeeeeee eeeee ee eeeeeee eee π-eeeeee eeeeeeeeeee ee eeeeeeeeee Meeee–Meeee eeeeeeeee eee eeeeeeeeee eee eee ee eeeeeeeeeeeeeeee eeee α,β-eeeeeeeeeee eeeeeeeeee ee eeeeeeeeeee. 8-Meeeee 8-eeeeee (M)-8-(8-eeeeeeeeeeeee)eee-8-eeeeeeeee (‌888‌) ee eee eeee eeeeeeee, eee ee eeeeee ee eeee eeeeee eee eeee eeee eeeeeeeeeeeeeeeeee eeee e eeee eeeeeee ee 8,8-eeeeee ee eee eeeeeeeeeee ee eee eeeeeeee ee e eeeeeeee eeeeeeee [e.e., Me(eee)8 ee MeMe8] ee eeeeeee eee eeeeeeeeeeeee eeeeeee ‌888‌ (‌Meeeee 888‌).[‌888‌]

‌Meeeee 888‌ Meeeee Meeeeeeeee ee Meeeeeeeeee[‌888‌]

‌Meeeeeeeeee 888‌

e eee = 8,8,8,8,8,8,8-eeeeeeeeeee-8,8-eeeeeeeeeeeeee-8,8-eeeeeee.

Meeeeeeeeeee Meeeeeeee

(8M*,8eM*,8eM*)-8-(eeee-Meeeeeeeeeeeeeeeeee)-8,8,8e,8,8,8e-eeeeeeeee-8M-eeeee-8-eee (‌888M‌) eee (8M*,8eM*,8eM*)-8-(eeee-Meeeeeeeeeeeeeeeeee)-8,8,8e,8,8,8e-eeeeeeeee-8M-eeeee-8-eee (‌888M‌):[‌888‌]

MMMMMMM: Meeeeeee eeeeeeeeeee eeee ee e eeeeee eeeeeeee ee eee eeeeeee eee eeeeee eeeeeeeee eeee eeeee.

M eeee ee 8-(eeee-eeeeeeeeeeeeeeeeeee)eeeeeeeee-8-eeeee (‌888‌; 8.88 e, 8.88 eeee) ee eeeeeee (88 eM) eee eeeeee eeeee ee e eeeeeeeeee ee MeMe8 (8.88 e, 8.8 eeee, 8.88 eeeee) ee eeeeeee (88 eM) ee ee eeeee M8. Meeee eeeeeeee ee ee eee ee. 88 eee, e eeee ee eeee-8,8-eeeee (88 eM) ee eeeeeee (88 eM) eee eeeee ee eee eeeeeee eeeeeee e eeeeeee. Mee eeeeeeeee eeee eee eeeeeee ee ee eee 8 e ee eeeee MMM eeeeeeeee eee eeeeeeee eeeeeeeeeee ee eee eeeee. Mee eeeeeee eee eeeeee eeee eee-eeee eee. ee MeMMM8 (888 eM), eee eeeeee eeee eeeeeeeee, eee eee eeeeeeeee eeeeeee eee eeeeeeeee eeee Me8M (8 × 888 eM). Mee eeeeeeee eeeeeeee eeee eeeeee eeee eee. ee MeMMM8 (8 × 88 eM) eee eeeee (8 × 888 eM), eeeee (MeMM8), eee eeeeeeeeeeee ee eeee e eeeeee eee; eeeee: 8.88 e. 8M MMM eeeeeeee ee eeee eeeeeee eeeeee e ee. 88:8 eeeee ee eeeeeeeeeeee ‌888M‌ eee ‌888M‌. Meeee eeeeeeeeeeeeee (eeeeee eee, eeeeeee/MeMMe 88:8) eeeeeeee eee eeee eeeee eeeeee ‌888M‌ [eeeee: 8.888 e (8.8%)] eee eee eeee eeeee eeeeee ‌888M‌ [eeeee: 8.88 e (88.8%)] eeee ee eeeeeeeee eeee.

‌888M‌: 8M MMM (888 MMe, MMMe8, δ): 8.88–8.88 (e, 8M), 8.88–8.88 (e, 8M), 8.88 (eee, M = 8.8, 8.8, 8.8 Me, 8M), 8.88–8.88 (e, M = 88.8, 8.8 Me, 8M, eee ee eee M ee e ee eeeeeeee ee δ 8.88), 8.88 (ee, M = 8.8, 8.8 Me, 8M), 8.88 (ee, M = 88.8, 8.8 Me, 8M), 8.88–8.88 (e, 8M), 8.88–8.88 (e, 8M), 8.88 (e, 8M), 8.888 eee 8.888 (8e, 8 × 8M); 88M MMM (88.8 MMe, MMMe8, δ): 888.8, 888.8, 888.8, 88.8, 88.8, 88.8, 88.8, 88.8, 88.8, 88.8.

‌888M‌: 8M MMM (888 MMe, MMMe8, δ): 8.88–8.88 (e, 8M), 8.88 (eee, M = 8.8, 8.8, 8.8 Me, 8M), 8.88 (ee, M = 8.8, 8.8 Me, 8M), 8.88 (ee, M = 88.8, 8.8 Me, 8M), 8.88–8.88 (e, 8M), 8.88–8.88 (e, 8M), 8.88 (eeee, M = 88.8, 8.8, 8.8, 8.8 Me, 8M), 8.88 (e, 8 M), 8.888 eee 8.888 (8e, 8 × 8M); 88M MMM (88.8 MMe, MMMe8, δ): 888.8, 888.8, 888.8, 88.8, 88.8, 88.8, 88.8, 88.8, 88.8, 88.8, 88.8, −8.8.

8-Meeeee 8-Meeeee (M)-8-Meeeeeeeeeeeeee-8,8-eeeee-8,8-eeeeeeeeeeeee (‌888‌, M8 = M; M8 = Me):[‌888‌]

M eeee ee 8-eeeeee 8-eeeeee (M)-8-(8-eeeeeeeeeeeee)eee-8-eeeeeeeee (‌888‌; 888 ee, 8.88 eeee, 8.8 eeeee) ee MM8Me8 (8.8 eM) eeeee ee eeeee eeeeeeeeee ee 8°M eee eeeee ee e eeee ee Me(eee)8 (888.8 ee, 8.88 eeee, 8.8 eeeee) ee MM8Me8 (8.8 eM). Mee eeeeeee eee eeeeeee eee 88 eee, eee eeee eeeeeeee (8.88 eeee) eee eeeee. Meeeeeee eee eeeeeeeee eee 88 e, eeeee eee eeeeeeeeee eee eeeeeeeeeee (MMM), eee eeee 8% MMe (88 eM) eee eeeee. Mee eeeeeee eeeee eee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeeeeee eeee MM8Me8 (8 × 88 eM). Mee eeeeeeee eeeeeeee eeee eeeeee eeee M8M (8 eM), eeeee (MeMM8), eee eeeeeeeee eeeeeeeeeeee (eeeeeee eeeeeee).

Mee eeeee eeeeeee eeee eeeeeeeeeee ee MM8Me8 (8 eM) eee eeeeeee ee eeeee ee ee eee 88 e, eeeee eeeeeeee eeeeeeee eeee eeeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeeeeeee eee eee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MM8Me8 8:8); eeeee: 888 ee (88%); ≥88% ee; [α]M +88.8 (e 8.88, MMMe8).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 88/8, 888.