Enantiopure sulforaphane analogues with various substituents at the sulfinyl sulfur: asymmetric synthesis and biological activities.

A convergent and high-yielding approach for the asymmetric synthesis of sulforaphane 2 and four analogues differently substituted at the sulfinyl sulfur has been developed. The key step of the synthesis is the diastereoselective synthesis of sulfinate ester 23-S(S), using the DAG (diacetone-D-glucofuranose)-methodology. The biological activity of these compounds as inductors of phase II detoxifying enzyme has been studied by determining their ability to activate the cytoprotective transcription factor Nrf2.