Synthesis of an eight-membered cyclic pseudo-dipeptide using ring closing metathesis

[GRAPHICS] Ring closing metathesis of diallylglycine 6 provided cyclic Z-olefin 7 in 8 0% yield, The reaction was promoted by substitution of the amide nitrogen w ith the 2,4-dimethoxybenzyl group allowing for the required cis diallylglyc ine amide rotamer, Removal of the protecting groups provided cyclic dipepti de 2, a constrained scaffold useful in peptidomimetic research.