Inversion of configuration in the displacement of lithium by hydrogen during a transannular 1,4-hydrogen transfer accompanying a [1,2]-Wittig rearrangement
摘要:
The presence of a 4-tert-butyl group on 2-lithio-6-(trans-1-propenyl)tetrahydropyran dramatically changes the rearrangement behavior, inhibiting the formation of [2,3]-Wittig rearrangement product and leading to a 1,4-transannular H-transfer to the lithium-bearing carbon atom with inversion of configuration.