Continuous Flow Synthesis of Highly Substituted Tetrahydrofurans

Diastereoselective Synthesis of 2,3,4-Trisubstituted Tetrahydrofurans via Thermally Reactive 1,5-Diene-tert-butyl Carbonates

We report that 3,3-dicyano-1,5-dienes bearing tert-butyl carbonates can be thermally converted to 2,3,4-trisubstituted tetrahydrofurans. The transformation relies on two thermally reactive functional groups, a 1,5-diene and a tert-butyl carbonate, that react cooperatively to yield the furan scaffolds by thermal Cope rearrangement, Boc deprotection, and oxy-Michael addition. Described herein is background related to the discovery, optimization, and scope of the key transformation and representative functional group interconversion chemistry for the tetrahydrofuran scaffolds.