Highly Regio- and Diastereoselective Synthesis of 6,7-Dihydro-4 H -furo[3,4- c ]pyran Derivatives through Pd-Catalyzed Formal (3 + 3) Allylic Cycloaddition of 2-Butene-1,4-diols with 2-(1-Alkynyl)-2-alken-1-ones.
Tuanli YaoJun-E SheTao LiXiangyang QinPublished in: Organic letters (2024)
A highly efficient synthesis of 7-vinyl-6,7-dihydro-4 H -furo[3,4- c ]pyran derivatives from 2-butene-1,4-diols and 2-(1-alkynyl)-2-alken-1-ones has been achieved with high regio- and diastereoselectivity (dr > 20:1) by Pd-catalyzed tandem heterocyclization/cross-coupling. The π-allyl palladium species Int II generated from 2-butene-1,4-diol by direct cleavage of the C-OH bond is the key to the success in this formal (3 + 3) cycloaddition reaction.