An asymmetric formal one-pot reaction of 4-hydroxycoumarins with unsaturated pyrazolones has been developed by merging a chiral bifunctional organocatalyst with molecular iodine, which furnished a series of optically active spiro[dihydrofurocoumarin/pyrazolone] heterocycles with spiro quaternary stereogenic centers in moderate to excellent yields (up to 99%) with excellent diastereoselectivities (up to >99 : 1 dr) and good to excellent enantioselectivities (up to 99% ee). The application in the gram-scale synthesis of chiral spiro[dihydrofurocoumarin/pyrazolone] compounds was also successfully realized.
![Graphical abstract: One-pot asymmetric synthesis of a spiro[dihydrofurocoumarin/pyrazolone] scaffold by a Michael addition/I2-mediated cyclization sequence](http://hg.y866.cn/compound/lib/scimg/usr/1/C7OB00986K.jpg)