To prepare Z -4-octene from 1-octyne, we can use the following synthetic route:1. Lindlar's Catalyst Hydrogenation:First, we need to convert the terminal alkyne 1-octyne into a cis-alkene Z -4-octene . This can be achieved using Lindlar's catalyst, which is a heterogeneous catalyst composed of palladium on calcium carbonate, and poisoned with lead II acetate and quinoline. The reaction conditions are as follows:1-octyne + H2 Z -4-octeneCatalyst: Lindlar's catalyst Pd/CaCO3, Pb OAc 2, quinoline Solvent: Ethanol or other suitable solventTemperature: Room temperatureLindlar's catalyst selectively hydrogenates alkynes to cis-alkenes Z-isomers without further hydrogenation to alkanes. This reaction is stereoselective and provides a high yield and selectivity for the desired Z -4-octene.The overall synthetic route is straightforward and involves only one step, which is the partial hydrogenation of 1-octyne using Lindlar's catalyst. This method is efficient and selective for the desired Z -isomer, providing a high yield of Z -4-octene.