ethyl 2,3-dimethylpenta-3,4-dienoate

but-2-ynyl 2-methoxyacetate

but-2-ynyl 2-(2-methoxyethoxymethoxy)acetate

4-(1-methylindol-3-yl)butan-2-one

buta-2,3-dien-2-yl-hydroxy-oxophosphanium