Lily Aldehyde

The carbonyl skeleton of lily aldehyde can be assembled by a mixed aldol condensation between propanal and the non-enolizable aldehyde, 4-tert-butylbenzaldehyde ... 

Dehydration and reduction of the carbon-carbon double bond completes the synthesis of lily aldehyde. 

Figure 4.64 shows the preparation of the hydrocinnamic aldehydes, another family of materials derived from benzene and which possess fresh, white-floral notes reminiscent of muguet (lily of the valley) and cyclamen. One of these, known as Lilial , Lilistralis or lily aldehyde, can also be prepared from toluene and that route is also included in this... 

Outlined below is a synthesis of a compound used in perfumes, called lily aldehyde. PRACTICE PROBLEM 19.11... 

Lilial (lily aldehyde, p-tert-butyl-a-methylhydro-cinnnamic aldehyde 5% pet Larsen 1983 De Groot et al. 1985 Santucci et al. 1987 Sugai 1994a Larsen et al. 1996 ... 

Lily aldehyde, used in perfumes, can be made starting with a mixed aldol condensation between two different aldehydes. Provide their structures. 

The sulfur dioxide can be recovered and recycled. The myrcenol, after purification by distillation, can condense with acrolein to produce Lyral [31906-04-4], an important aldehyde with a strong-lasting odor similar to Lily-of-the-valley (92). 

Hedychium coronarium Koen. Shan Ren (Ginger lily) (flower, rhizome) Sesquiterpenes, phenols, aldehyde, ketone, 1,8-cineole, camphene, beta-pinene.60-195 Stimulant. 

The most classical artificial substances used in perfumery are as follows (Figure 5). Hydroxycitronellal (99) was found to exhibit the odor of lily of the valley, the essential oil of which is not possible to prepare in the first place. Other classics include ct-amylcinnamaldehyde (100) and musk ketone (101), which were discovered to be good substitutes for jasmine and musk, respectively. Furthermore, perfume No. 5 (Chanel, launched 1921) contained 2-methylundecanal, 1 with so unique an aroma character that it established No. 5 as the pioneer of a new fragrance class — floral aldehydic. 

Chemical purity and organoleptic purity are not synonymous. For example, the aldehyde (Structure 1) was discovered when a sample of the alcohol (Structure 2) was found to have the expected muguet (lily of the valley) odor (21). The alcohol was prepared from 4-f-amylcyclohexanone (Structure 3) by the scheme shown in Fig. 2. The reduction product contained mostly the desired alcohol (Structure 2) but with some of the isomeric material (Structure 4) in which the double bond had moved into the ring. Flowever, gc-sniffing revealed that neither of these was responsible for the muguet odor of the sample, but rather that it was caused entirely by a tiny trace of aldehyde (Structure 1). Unless organoleptic purity is verified by such techniques, a risk of mistaken attribution of an odor... 

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-... 

Solvents include numerous chemical classes alcohols, ketones, ethers, esters, glycols, aldehydes, saturated and unsaturated aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, carbon disulfide, and mixtures (Lilis 1992). These chemicals extract, dissolve, or suspend insoluble materials such as fats and polymers (Joint WHO/Nordic Council of Ministers Working Group 1985). Solvents most associated with psychiatric illness are carbon disulfide, halogenated hydrocarbons, aromatic hydrocarbons, and mixtures. 

C13H22O2, Mr 210.32, bpo iy kpa 120-122 °C, df 0.9941, rag0 1.4915, is a fragrance substance that does not occur in nature. It is a colorless, viscous liquid with a sweet odor reminiscent of lily of the valley. The aldehyde can be prepared by a Diels -Alder reaction of myrcenol and acrolein in the presence of a Lewis catalyst (e.g., zinc chloride) [117] ... 

Ci2Hi80, Mr 178.27, is not reported as being found in nature. It is a viscous liquid or crystalline mass, mp 22 °C, po.oi3 kPa 74-76 °C, df 0.960, ng° 1.515-1.518, with a fresh floral odor, reminiscent of lily of the valley and linden blossoms. It is prepared by reaction of 3-methylbenzyl chloride with 2-methylpropanal in the presence of tetrabutylammonium iodide and reduction of the resulting aldehyde with NaBH4 [143]. 

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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