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
37.1.1.7.4 Method 4: Synthesis by a Two-Step Procedure from an Acetal

DOI: 10.1055/sos-SD-037-00003

Van Orden, L. J.; Jasti, R.; Rychnovsky, S. D.Science of Synthesis, (20083743.

Typically, when cyclic acetals are treated with a Lewis acid and a nucleophile, a 2-substituted cyclic ether is formed.[‌100‌] In the presence of bromodimethylborane, however, cyclic acetals 167 are transformed into acyclic bromo ethers that then undergo alkylative cleavage to provide acyclic hydroxy ethers 168 (Scheme 57).[‌101‌] The authors report that in an anhydrous environment, the α-bromo ether intermediates are determined to be stable when maintained at a low temperature. This procedure is convenient because the synthesis of these starting acetals is relatively straightforward, and it avoids the isolation and direct use of toxic α-halo ethers.

Meeeee 88 Meeeeeeeee Meeeeeee ee α-Meeee Meeeee eeee Meeeee Meeeeee[‌888‌]

Meeeeeeeeee 88

e MeM Me Meeee (%) Mee
8 MeMMMe8 M 88 [‌888‌]
8 MeMM MM 88 [‌888‌]
8 MeMeMe Me 88 [‌888‌]
8 MeMM MMe 88 [‌888‌]
8 MeMM MM 88 [‌888‌]
8 Me8MeMe Me 88 [‌888‌]
8 MeMM MMe 88 [‌888‌]

Meeeeeeeeeee Meeeeeeee

8-(Meeeeeeeee)eeeeee-8-ee (888, e=8; Me=Me); Meeeeee Meeeeeeee:[‌888‌]

Me e eeee ee 8-(eeeeeeeeee)eeeeeeeeeeeeeee (888, e=8; 8.88e, 8.8eeee) ee MM8Me8 (88eM) ee 88°M eee eeeee Me8MMe (8.8eeee). Meee eeeeeee eee eeeeeee ee eeee eee 88eee ee eeee eeeeeeeeeee eee eeee eMe8MMe (8.8eeee) eee MeMeMe (8.8eeee) eeee eeeee eeeeeeeeeeee eee eee eeeeeeeee eeeeeee eee eeeeeee ee eeee ee 88°M. Mee. ee MM8Me eee eeeee eee eee eeeeeee eeeee eee eeeee (MeMM8) eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeee eeeeeeeeeeeeee ee eee eeeee eeeeeee eeeeeeee 888 (e=8; Me =Me); eeeee: 88%.

References


Cookie-Einstellungen