Vanillin

One of the first synthetics used in perfumery, it's still one of the most important and widely used raw materials to this day. It's what most people know is the smell of vanilla since it's also used widely in the flavourings industry (real vanilla is far less sweet and more woody then most people realise). A touch of vanillin goes a long way towards adding a long lasting sweetness to your perfume compositions. Larger amounts contribute to an overt vanilla note, but be careful since too much can make your perfumes sickeningly sweet and synthetic smelling.