Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
25.1.5.2 Method 2: Synthesis from Glycols

DOI: 10.1055/sos-SD-025-00101

Kalesse, M.Science of Synthesis, (200725139.

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 8.8e (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; 88.8e, 8.88eee) ee eeeeeee MeMM (888eM) eee eeeeee ee 88.888.8°M. Meeee ee M8MM8 (8.8eM) eee eeeee eeee 88eee eeeee ee eeeeeeee eeeeeeeeeee ee 88.888.8°M eee eeeeeeeeee. Mee eeeeeee eee eeeeee ee 888.8888.8°M eee eeeeeee eee 888eee eee eeee eee eeeeee eeee eeeeeeeee. Me eee eeeeeee eeeee eee eeeee eeeeeeeeeee (888eM). Mee eeeeeee eee eeeeeee eee 888eee eee eeee eee eeeeee eeee eeeeeeeee. Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee M8M (888eM) eee 8% ee MeMMM8 (8×888eM) (MMMMMMM: eeeeeee) (eeeeeee eeeee eeeee eeeeee eeee eee eM8.8). Mee eeeeeee eeeee eee eeeeeeee eeee Me8MM8 (88e) eee 88eee, eee eeeeeee eee eeeeeeee, eee eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee; eeee eeee ee eee; eeeee: 88.8e (88%).

(±)-[8,8-Mee(eeee-eeeeeeeeeeeeeeeeeee)-8-eeeeeeeeeeeee](8,8,8-eeeeeeeeeeeeeeee)eeeeeeeeeeee (88); Meeeeee Meeeeeeee:[‌8‌]

MM8MMe8 (8.88eM, 8.8eeee) eee eeeee eeeeeeee ee e eeeeeee eeee ee eeee 88 (8.8e, 8.8eeee) ee eeeee MMM (88eM) eeeee eeeee ee ee. Meeee 8e, eee. MeMMM8 eee eeeee ee eee eeeeeee eeeeee eeeeeeeeee eeee MeMMe (8×88eM) 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: 8.8e (88%).

References