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.
1.6.3.1 Reduction of Diols by Metal-Free Catalysis

DOI: 10.1055/sos-SD-226-00133

Tin, S.; de Vries, J. G.Science of Synthesis: Catalytic Reduction in Organic Synthesis, (20171233.

Although the deoxydehydration of vicinal diols often requires a transition-metal catalyst,[‌33‌,‌34‌] there are examples of methods where the latter is not required. One such practical method involves the use of formic acid as both the source of hydrogen and the catalyst for the reduction of vicinal diol groups.[‌35‌] Some examples with good to high yields of products 8 are shown in Table 1. Notably, the side products of this reaction are water and carbon dioxide (see Scheme 8 for the proposed mechanism). For cases in which the substrate contains additional hydroxy groups (e.g., glycerol, entries 1 and 2), the formation of allyl formate is also observed, but it can easily be separated from the product (see below for details). The conversion of glycerol into prop-2-en-1-ol can even be performed on a 500-gram scale (5.4 mol of starting material); 265 grams (84% yield) of the desired product was obtained. This proves that the method is scalable. It has also been shown that the configuration of the newly formed double bond depends on the relative stereochemistry of the hydroxy groups in the starting material. In the deoxydehydration of decane-3,4-diol, either the E- or Z-product is obtained selectively, depending on the stereochemistry of the starting material (entries 9 and 10). This suggests that exclusively syn-elimination of the hydroxy groups occurs.

Meeeee eeeee eee eeee ee eeeeeeeee eeeeeeeeeeee. Me eee eeeee, eee eeeeeee eeeeee eee eee ee eeee eeeee. Mee eeeeeeee ee eeeeeee eee eeeeeeeee eeee eeeeee eeeee-eeeee eeee eeee eeeeeeeeeeee. Meee eeeeeeeeeee ee eeeeeeeeee eeee eeee eeeeeeee eee eee eeeeeeeeeeeee ee eee eee eeeeeeeee eeeeeeeeeeeee ee eeeeee-8,8-eeee eeeeeeeee eeeee. Meeeeeee eeee eeeeeeee ee eee eeeeeeeeeeeeee eeeeeee eeeeee ee e eeeeeeee eeeeeeee ee eee eeeeee eeeeeee ee eeeeeeeeeee eeeeee ee eee eeeeeeee eeeeeeee, ee eeee eeeee eeee eee eeeeee ee eeeeeee ee eee-eeeee ee eeeeee eeeeeeee eee eeee ee eeeeeeee eeeeeeeee.

Meeee 8 Meeeeeeee ee Meeeeee Meeee ee Meeeeee Meeee Meeeee Meee[‌88‌]

Meeee Meeeeeee Meeeeeee Meeee (eeee) Meeeeee Meeee (%) Mee
8 88 88 [‌88‌]
8 888 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
8 88 88 [‌88‌]
88 8.8 88 [‌88‌]

Meeeee 8 Meeeeeee Meeeeeeee eee eee Meeeee Meee Meeeeeee Meeeeeeeeeeee ee Meeeeee Meeee[‌88‌]

Meee eeeeee eee eeeeee ee ee eeee eeeeee ee eeeeeeeee eeeeeeeee, eeee ee ee eee eee-eeee eeeeeeeee ee eeeee-8,8-eeeee eeee eeeeeee (Meeeee 8).[‌88‌] Meeeeeee eee eeeee ee eee eeeee eeee (eee eeeeee eeee eeeeeeee eeeeeeeeeeeeeeee) eee eee eeeeeeee, eeeee-8,8-eeeee eee eeeeeeee ee eeee eeeeee eeeee eee eeeeee eeee. Meeeeee, eeeeeeee eee eeeeeeeeeee eee eee eeeeeee eeeee-8,8-eeeeee eeeeeee ee eeee eeeeeee, eee ee eee eeee eeeeeeee ee eeeee-8,8-eeee-8-ee, eee eeeeeee ee eee eeeeeeeeee ee eeee eeeeeee.

Meeeee 8 Mee-Meee Meeeeeeee ee Meeee-8,8-eeeee eee Meeeee Meee Meeeeeee Meeeeeeeeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

Meee-8-ee-8-ee (Meeee 8, Meeee 8); Meeeeee Meeeeeeee:[‌88‌]

M eeeee eeeeeeee eeee e eeeeeeeeeeeee eeeeee, e eeeeee eeeeeeeee, eee e eeeeeeeeee eeeee eee eeeeeee eeee eeeeeeee (88.8 e, 888 eeee) eee 88% MMM8M (8.88 eM, 88 eeee). Mee eeeeeee eee eeeeeee eeeee e M8 eeeeeeeeee eee 88 eee, eee eee eeee eeeeee ee 888 °M eeee eeeeeeeeee ee eee eeeeeeeeee. Meee eeeeeeeeeeee eee eeeeee, eee eeeeeee eee eeeeee ee ee eee eeee MMM8M (8.88 eM, 88.8 eeee) eee eeeee. Mee eeeeeee, eeeeeeeeeeee, eee eeeeeee eeeeeee eee eeeeeeee ee eee eeee eeeeee. Mee eeee eeeeeee ee MMM8M (8.88 eM, 88.8 eeee) eee eeeee, eee eee eeeeeeeee eee eeeeeeee eeeee. Meeee eeee eeee, eee eeeeeeeeeee eeee eeeeeeee, M8MM8 eee eeeee, eee eee eeeeeee eeeee eee eeeeeeeee. Meeeeeeeeeee eeeeeeeee eee eeeee eeeeeeee; eeeee: 8.88 e (88%).

References


Cookie-Einstellungen