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
20.6.1.7 Method 7: Lactonization of Unsaturated Carboxylic Acids

DOI: 10.1055/sos-SD-020-01369

Maier, M. E.Science of Synthesis, (2007201481.

Electrophile-mediated cyclizations of alkenoic acids represent a powerful route to certain lactones.[‌281‌,‌282‌] Generally, this approach is limited to four- to seven-membered lactones. The cyclization is initiated by an electrophilic attack on the double bond, generating a carbenium ion or onium intermediate. This is followed by intramolecular attack of the carboxylic oxygen. Under kinetically controlled conditions the ring size is governed by the Baldwin rules. For example, with an onium intermediate the five-membered lactone is favored over the six-membered isomer (5-exo-tet vs 6-endo-tet).[‌283‌]

References


Cookie-Einstellungen