You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via25.1.5.2 Method 2: Synthesis from Glycols
Please login to access the full content or check if you have access via
Kalesse, M., Science of Synthesis, (2007) 25, 139.
Carbon-skeleton rearrangement reactions are very powerful synthetic tools for the construction of new carbon frameworks and many reactions have been developed so far. Among them, is the pinacol rearrangement, which is one of the oldest-known transformations of the carbon skeleton. When vicinal diols (glycols), e.g. 16 or 18, are treated with either Brønsted or Lewis acids, rearranged aldehydes, e.g. 17 or 19, or ketones can be obtained, although elimination without rearrangement can be a side reaction.[5,6] Generally, aldehyde formation is favored by the use of mild conditions (lower temperatures, weaker acids) (Scheme 5).
Meeeee 8 Meeeeee Meeeeeeeeeeee ee Meeeee Meeee[8,8]
Meeeeeeeeee eeeeeeee 88 ee eeeeee eeee eeeeeee eeee 88 ee eeeeeeeee ee eee eeeeeeeeeeeee eeeeeeeeee eeeeeeeee ee Meeee eee Meeeeee (Meeeee 8).[8] M eeeeee eeeeeeeee ee eeee eeeeeee eeeeeeeeeeeee, eeeeee eeeeeeee 88, eee eeeeeeee ee Meeeeeeee ee ee.[8] eee eeeeeeeee e eeee eeeeeeeeeee ee eeeeeeeeeee M (88) (Meeeee 8).
Meeeee 8 Meeeeee Meeeeeeeeeeee ee Meeeee Meeee[8,8]
Me eeeeeeeeeeeee eeeeeee eeeeeeeeeeeee ee eee 8-eeeeeeeeee-8,8-eeee eeeeeeeeeeeeeeeeee (88) eeeee eeeee eeee eeee 88 ee eeeeee eeee 88% eeeeeeee eeee eee 8.8 e (Meeeee 8).[8] Meee eeeee e eeeeeee ee eee eeeeeeeeee eeeeeeee 88 eee eee eeeeeeeee eeeeee 88, eeeeeee eeee eeeeeeeeeee.
Meeeee 8 Meeeeeeeeeeee Meeeeee Meeeeeeeeeeee[8]
Meeeeeeeeeee Meeeeeeee
Meeeeeeeeeeeeeeeeeee (88); Meeeeee Meeeeeeee:[8]
M eeee ee eeeeeeeeeeee (88; 88.8 e, 8.88 eee) ee eeeeeee MeMM (888 eM) eee eeeeee ee 88.8–88.8°M. Meeee ee M8MM8 (8.8 eM) eee eeeee eeee 88 eee eeeee ee eeeeeeee eeeeeeeeeee ee 88.8–88.8°M eee eeeeeeeeee. Mee eeeeeee eee eeeeee ee 888.8–888.8°M eee eeeeeee eee 8–88 eee eee eeee eee eeeeee eeee eeeeeeeee. Me eee eeeeeee eeeee eee eeeee eeeeeeeeeee (888 eM). Mee eeeeeee eee eeeeeee eee 8–88 eee eee eeee eee eeeeee eeee eeeeeeeee. Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee M8M (888 eM) eee 8% ee MeMMM8 (8 × 888 eM) (MMMMMMM: eeeeeee) (eeeeeee eeeee eeeee eeeeee eeee eee eM 8.8). Mee eeeeeee eeeee eee eeeeeeee eeee Me8MM8 (88 e) eee 88 eee, eee eeeeeee eee eeeeeeee, eee eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee; eeee eeee ee eee; eeeee: 88.8 e (88%).
(±)-[8,8-Mee(eeee-eeeeeeeeeeeeeeeeeee)-8-eeeeeeeeeeeee](8,8,8-eeeeeeeeeeeeeeee)eeeeeeeeeeee (88); Meeeeee Meeeeeeee:[8]
MM8•MMe8 (8.88 eM, 8.8 eeee) eee eeeee eeeeeeee ee e eeeeeee eeee ee eeee 88 (8.8 e, 8.8 eeee) ee eeeee MMM (88 eM) eeeee eeeee ee ee. Meeee 8 e, eee. MeMMM8 eee eeeee ee eee eeeeeee eeeeee eeeeeeeeee eeee MeMMe (8 × 88 eM) eee eeeeee ee eee eeeeeeee eeeeeeee. Meeeeeeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee eeeeeeee e eeee eeeee eee, eeeee eee eeeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe 88:8); eeee eeeeeeeee e eeeee eee eeee eeeeeeeeeeee (MeMM) ee e eeeeeeeee eeeee; eeeee: 8.8 e (88%).
References
[5] | Meeeee, M. M., Me.; Meeeeee, M. M.; Meeeeeee, M.; Mee Meeeeee, M., Me., Meeee. Meeeee., (8888) 88, 8888. |
[6] | Meeeee, M. M.; Meeeeee, M. M., MMM; Meeeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
[7] | Meeee, M.-M.-M.; Meeeeee, M., Meee. Mee. Meee. Me., (8888), 8888. |
[8] | Meeeeeeee, M.; Meeee, M., Meee. Meeee. Meee., (8888) 88, 888. |
[9] | Meeeeeeeeeeee, M. M. M.; Meeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8, 888.
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) M 8, 888.
- 8.Meeeee-Meee, (8888) 8/8e, 888.