Reductions via Boranes: A New, Convenient Method for the Preparation of 3-Substituted Esters and Thioesters of 3,4-Dihydrocoumarin

Article abstract of DOI:10.1055/s-1986-31643

Reduction of various O-ethyl coumarin-3-carboxylates and O-ethyl coumarin-3-thioncarboxylates with diborane, borane dimethyl sulfide, 9-borabicyclo<3.3.1>nonane, and bisethane-diborane lead to the corresponding 3,4-dihydro derivatives with good yields.