Preparation of Diastereomerically Pure Dilignol Model Compounds

A gram-scale synthetic access to diastereomerically pure dilignol beta-O-4 type model compounds, which represent valuable candidates for studies of lignin cleavage and valorization, is described. Following a straightforward procedure both diastereoisomers of 1,3-dilignols can be prepared. In the key-step, tert-butyl aryloxy esters are used as enolate precursors for additions on aldehydes. After separation, the resulting erythro and threo beta-hydroxy esters are independently reduced to afford the target compounds in high yields.