Lily of the valley odour

This alcohol appears to be almost odourless, but when a dilute solution in alcohol is allowed to evaporate slowly, a very fine lily-of-the-valley odour is developed, together with the suggestion of cedar-wood oil. 

Figure 13.10). The two binding sites were in similar areas of the protein. In both cases, the work involved molecular modelling rather than isolation and characterisation techniques and is therefore circumstantial. However, it is interesting to note that both molecules have similar muguet (lily of the valley) odours. 

The oils are entirely different in odour from the normal oil, and one would describe them as a blend of lavender and petitgrain rather than the normal linaloe (lily of the valley) odour. 

Linalyl Propionate.—This ester is also produced by condensing the free alcohol and the free acid by means of sulphuric acid. It has a somewhat fruity odour recalling that of bergamot, and is especially suitable for perfumes of the lily of the valley type. It is a colourless oil, boiling at 115° at 10 mm. pressure. 

Since the blossom oil of lily of the valley is not commercially available, the perfumers have to rely on synthetic substitutes, such as hydroxy-citronellal (1), Lilial (3) and Bourgeonal (6) to create their muguet fragrances. The oldest lily of the valley odorants, hydroxycitronellal and cyclamen aldehyde (2) (Winthrop Chem. Corp., 1929), were discovered by chance. Serendipity still continues to play an important role. Anselmi et al. (1992) synthesized and organoleptically screened a series of 38 tetrahydropyranyl ethers. This class of compounds was chosen because of their ease of synthesis and purification, and because of their stability in alkaline media, conditions under which aldehydes tend to undergo aldol condensations. Two compounds (24 and 25) were described as having a white, floral odour reminiscent of hydroxycitro-... 

Figure 14.4 Natural compounds with odours reminiscent of lily of the valley...

For example, the addition of acrolein to myrcene gives a product known by trade names such as Myrac Aldehyde or Empetal . The product is a mixture of isomers because the dienophile can line up in two orientations relative to the diene. For simplicity, only the major isomer, in which the two substituents on the cyclohexane ring are 1,4 relative to each other, is shown. Hydration of the acyclic double bond of Empetal gives a hydroxy-aldehyde, known as Hydroxy empetal or Lyral . Lyral possesses a fine odour reminiscent of the delicate odour of the flowers of lily of the valley and is widely used in perfumery. 

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