Use of RCM reactions for construction of eight-membered carbocycles and introduction of a hydroxy group at the juncture between five- and eight-membered carbocycles.

Model studies for total synthesis of YW3699 were carried out in order to introduce a hydroxy group at the ring juncture between 5- and 8-membered carbocycles. The five-membered ring part, hydrazone, and aldehyde with a cyclohexane ring were connected by the Shapiro reaction, followed by conversion to diketones, which were treated with IBX to afford hydroxylated models.