Fig. 1: Monomer synthesis overview.

Synthesis pathway with yields and diastereomeric excess (de) of intermediates for the production of the lactam isomers 5-3S and 5-3R (yields refer to the small-scale experiments from purified starting material). The labelling of the stereo-centre C3 at all intermediates follows the recommendation for terpene carbon skeleton numbering of M. W. Grafflin, which suggest that the initial carbon labels of (+)-3-carene are fixed also in case of functionalization44.