A Cascade Approach to Naphthalene Derivatives from o-Alkynylbenzaldehydes and Enolizable Ketones via in-situ-Formed Acetals

作者：Manojveer Seetharaman; Balamurugan Rengarajan^*

来源：European Journal of Organic Chemistry, 2015, 2015(19): 4254-4260.

DOI：10.1002/ejoc.201500497

• Fused-ring systems
• Cyclization
• Aldol reactions
• Acetals

Using the in-situ-formed acetal strategy, a facile approach has been developed to synthesize naphthalene derivatives from o-alkynylbenzaldehydes and enolizable ketones. In situ acetal formation assists the condensation between o-alkynylbenzaldehydes and enolizable ketones to give chalcone derivatives under BrOnsted acidic conditions. In situ acetal formation facilitates the reaction by increasing the electrophilicity of the carbonyl carbon of the o-alkynylaldehyde through oxonium ion formation, and also by enhancing the nucleophilicity of the carbon of the ketone through the formation of an enol ether. The formed chalcones undergo trans to cis isomerization to effect alkyne-carbonyl metathesis to give naphthalene derivatives.

• 出版日期2015-7