We report the synthesis of single enantiomers of two epoxy-mycolic acids containing an α-methyl-trans-alkene.

•The synthesis of dimycolyl triarabinose fragments of the mycobacterial cell wall is described.•The mycolic acids were single stereoisomers of each major common class of mycolic acid.•The method used is a modification of that used to synthesize such fragments from complex mixtures of natural mycolic acids.An efficient synthetic approach to tri-arabino di-mycolates, using structurally defined synthetic α-, keto and methoxy mycolic acids is described.