We describe alternative access to prostacyclin analogues by means of two ω-side chain addition strategies: Grignard reagent addition to an α,β-unsaturated Weinreb amide, followed by diastereoselective reduction of the corresponding enone system, and implementation of Seebach's alkylation chemistry. These strategies have led to the syntheses of biologically active prostacyclin analogues isocarbacyclin and 15R-16-(m-tolyl)-17,18,19,20-tetranorisocarbacyclin (15R-TIC), with modest to excellent diastereoselectivity.