Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
2.2.4.12.1 meso-Anhydride Desymmetrization

DOI: 10.1055/sos-SD-205-00205

Hof, K.; Lippert, K. M.; Schreiner, P. R.Science of Synthesis: Asymmetric Organocatalysis, (20122373.

The groups of Chen,[‌250‌] Connon,[‌251‌] Pedrosa,[‌252‌] and Chin and Song[‌253‌,‌254‌] developed thiourea-catalyzed protocols for the desymmetrization of meso-anhydrides via alcoholysis to obtain enantioenriched hemiesters with high yields and good enantioselectivities; results from Connon[‌251‌] and Pedrosa[‌252‌] are shown in Scheme 62 and Table 1. Chen and Wang also reached enantioselectivities of 8295% with good yields (8897%), and utilized the developed protocol in a reaction step in the total synthesis of (+)-biotin.[‌250‌] Song and Chin also achieved high enantioselectivity of >91% with good yields of >88%, but the other groups demonstrated broader scope.[‌253‌] The desymmetrization of anhydrides requires simultaneous activation of the alcohol and the ester functions, and the bifunctional catalyst presumably assumes this role. The enantioselectivity is independent of the relative stereochemistry of the starting meso-anhydrides, because endo- as well as exo-tricyclic anhydrides react at the same carbonyl group (Table 1, entries 1, 2, 5, and 10). Huang and co-workers published a synthesis of an asymmetric dihydropyridin-2-one derivative utilizing an anhydride desymmetrization step.[‌255‌]

Meeeee 88 Meeeeeeee eee Meeeeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeeeee eeee Meeeeeee Meeeeeeee[‌888‌,‌888‌]

Meeee 8 Meeeeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeeeee eeee Meeeeeee Meeeeeeee[‌888‌,‌888‌]

Meeee Meeeeeee Meeeeeee Meeeeeee Meee (°M) Meee (e) Meeeeee Meeee (%) ee (%) Mee
8 888 ee 88 88 >88e [‌888‌]
8 888 ee 88 88 88e [‌888‌]
8 888 ee 88 88 88e [‌888‌]
8 888 ee 88 88 88e [‌888‌]
8 888 ee 88 88 88e [‌888‌]
8 88 ee 88 88 88e [‌888‌]
8 88 8 88 88 88e [‌888‌]
8 88 8 88 88e 88e [‌888‌]
8 888 8 88 88 88e [‌888‌]
88 888 ee 888 88 88e [‌888‌]

e Meeeeeeeeeee eeeeee eeeeeeeeee eeeee eeeeeeeeeeeeee ee e 8-eeeeeeeeeee eeeee.

e Meeeeeeeeeee eeeeee eeeeeeeeee eeeee eeeeeeeeeeeeee eeee (M)-8-(8-eeeeeeee)eeeeeeeeee ee 8M-MMM eeeeeeee eee/ee eeeeeeeee ee MMM-MMMM.

e Mee eeeeeeee eeeeeeeeeeeee ee eee eeeeeee eee eee eeeeeeeeee.

Meeeeeeeeeee Meeeeeeee

Meeeeeeeeeeeeee Meeeeeeeee (Meeee 8, Meeeeee 88, 8, eee 88); Meeeeee Meeeeeeee Meeee Meeeeeee 888:[‌888‌]

Meeee e M8 eeeeeeeeee eee ee ee, eeeee MeMM (888µM, 8.8eeee) eee eeeee eeeeeeee ee e eeee ee eee eeeeeeeee 888 (8.8eeee) eee eeeeeeee 888 (88.8ee, 8.888eeee) ee eeeee e-MeMMe (88eM, 8.888M). Mee eeeeeee eee eeeeeee eeeee eeeeeeee eeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeeeeeee, eee eeeeeee eee eeeeeeeee eeee MM8Me8 (8eM), eee eee eeee eee eeeeeeeee eeee eee. ee Me8MM8 (8×8eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeeeeeee eeee 8M MMe eee eeeeeeeee eeee MeMMe (8×88eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8), eee eeeee eeeeeee ee eee eeeeee eeeee ee eeeeeeeeee, eee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee.

Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee ee eeeeeee eeeeeeee eee/ee MMMM eeeeeeee. Meeee eeeeeeeeee ee eee eeeeeeeee 888 eeee eee eeeeeeeeeeeee 8-eeeeeeeeeee eeeeee, eee eeeeeeeeeeee eeeeee eee eeee eeeeeeeeee ee MMMM eeeeeeee [Meeeee Meeeeeeee MM ee Meeeeeeee MM-M ee MM-M (eeee 888×8.8ee); eeeeee/eMeMM].

Meeeeeeeeeeeeee Meeeeeeeee (e.e., Meeee 8, Meeee 8); Meeeeee Meeeeeeee Meeee Meeeeeee 88 ee Meee Meeeeeeeeee:[‌888‌]

Mee eeeeeeeee (8.8eeee) eee eeeeee ee e 88-eM eeee eeeeeeee eeee e eeeeeee eee eee eeeeeeee 88 (8.8ee, 8.888eeee). M eeeeee eee eeeee ee eee eeee, eeeee eee eeeeeee eeee eeeee eee eeeee e-MeMMe (88eM) eee eeeee. Meeee MeMM (888µM, 8.8eeee) eee eeeee eeeeeeee ee eee eeeeeee eeeeeee e eeeeeee. Mee eeeeeee eee eeeeeee ee ee eee eee eeee eeeee ee Meeee 8. Meee eeeeeeeeee eee eeeeeeeeee ee MMM ee 8MMMM eeeeeeeeeeee. Mee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeeeee eeee 8.888.888ee). Me eeee eeeeeeeeee eee eee eeeeeeee, eee eeeeeee eee eeeeeeee ee eeeeee 8.8M MMe (88eM). Mee eeeeeee eeeee eee eeeeeeeee eeee MeMMe (8×88eM) eee eee eeeeeeee eeeeeee eeeeee eeee eeeee (MeMM8). Mee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee eee eee eeeee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeeeee eeee 8.888.888ee).

Mee eeeeeeeeeeee eeeeee eee eeeeeeeeee ee 8MMMM eeeeeeeeeeee eeeee eeeeeeeeeeeeee eeee (M)-8-(8-eeeeeeee)eeeeeeeeee eee/ee ee MMMM-MMMM eeeeeeee [MM-M eeeeee (8.8ee ×88ee), eeeeee/eMeMM 88:88] eee ee eeeeeee eeeeeeee.

Meeeeeeeeeeeeee Meeeeeeeee (Meeee 8, Meeeeee 8 eee 8); Meeeeee Meeeeeeee Meeee Meeeeeee 88 ee Mee Meeeeeeeeee:[‌888‌]

Mee eeeeeeeee (8.8eeee) eee eeeeee ee e 88-eM eeee eeeeeeee eeee e eeeeeee eee eee eeeeeeee 88 (8.8ee, 8.888eeee). M eeeeee eee eeeee ee eee eeee, eeeee eee eeee eeeeeee eeee eeeee. Meeee e-MeMMe (88eM) eee eeeee eee eee eeeeeee eee eeeeee ee 8°M. Meeee MeMM (888µM, 8.8eeee) eee eeeee eeeeeeee ee eee eeeeeee eeeeeee e eeeeeee. Mee eeeeeee eee eeeeeee ee 8°M eee eee eeee eeeee ee Meeee 8. Meee eeeeeeeeee eee eeeeeeee ee MMM ee 8MMMM eeeeeeeeeeee. Mee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee.

Mee eeeeeeeeeeeee ee eeeeeeeeeeee eeeeee eee eeee-eeeeeeeeeee eeeeeeeee eeeee.

References


Cookie-Einstellungen