(R,E)-methyl 5-(1-bromoethylidene)-3-(but-2-ynyl)-2-oxotetrahydrofuran-3-carboxylate

(S,E)-methyl 5-(1-bromoethylidene)-3-(but-2-ynyl)-2-oxotetrahydrofuran-3-carboxylate

dimethyl 2-(but-2-yn-1-yl)-2-((4,5-dimethyl-1-(4-methylbenzyl)-1H-pyrrol-3-yl)methyl)malonate

dimethyl 3,4-diethylcyclopent-3-ene-1,1-dicarboxylate

dimethyl 2-(but-2-yn-1-yl)-2-((1-(4-chlorobenzyl)-4,5-dimethyl-1H-pyrrol-3-yl)methyl)malonate