Acid-Promoted Cascade Cyclization to Produce 2-(4-Alkoxyaryl)-3,4-Fused Tricyclic Dihydrobenzopyrans via a Vinylidene para-Quinone Methide Intermediate

作者：Choi Dongil; Shiga Naoki; Franzen Robert; Nemoto Tetsuhiro

来源：European Journal of Organic Chemistry, 2018, 2018(15): 1785-1788.

DOI：10.1002/ejoc.201800013

• Cascade reactions
• Dihydrobenzopyrans
• Fused-ring systems
• Synthetic methods

We developed a novel method for synthesizing 2-(4-hydroxyaryl)-3,4-fused tricyclic dihydrobenzopyrans with 2,3-syn and 3,4-syn motif based on the acid-promoted cascade cyclization via vinylidene para-quinone methide intermediates. Using easily prepared linear substrates, TFA-promoted cascade cyclization proceeded in the presence of triethylsilane, affording a series of five to seven-membered ring-fused dihydrobenzopyran derivatives in moderate to excellent yield in a highly diastereoselective manner. The developed method provided new access to potent and selective ER agonists.

• 出版日期2018-4-23