Fig. 12
Top left: Overall reaction for the synthesis of Wieland-Miescher Ketone (WMK) from methyl vinyl ketone and 2-methylcyclohexane-1,3-dione. Top right: The phase one synthesis plan corresponding to this overall reaction. It has decalin as skeleton molecule and a bond set of size two. Bottom: Detailed reaction mechanism of the L-proline catalyzed Robinson annulation to yield WMK. The red arrows indicate the affixation and acclimatization steps in the synthesis tree (top right). Note that both bond fixes require a lot of electron rearrangement shown as arrows in the two bracketed reaction transition states. In all subfigures, the bonds of the bond set are shown by red lines