2008

Phenol ethersQ 0270 AuCl-Catalyzed Synthesis of Benzyl-Protected Substituted Phenols: A Formal

[3 + 3] Approach. — An efficient synthesis of highly substituted benzyl-protected phenols, e.g. (I) or (XII), involves the reaction of enals or enones with lithiated benzyl allenyl ether followed by Au-catalyzed intramolecular cyclization of the allenyl alkenyl carbinol derivatives thus formed. In the case of enals, the allenyl alkenyl carbinol de-rivatives are isolated as stable compounds, e.g. (I) and (III). For enones, these interme-diates are directly cyclized. Functional groups like tethered alkenes or ketals remain intact under the applied conditions. — (HUANG, X.; ZHANG*, L.; Org. Lett. 9 (2007) 22, 4627-4630; Dep. Chem., Univ. Nev., Reno, NV 89557, USA; Eng.) — Mischke

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