Carvone benzaldehyde

Aldehydes occur naturally in essential oils and contribute to the flavors of fruits and the odors of plants. Benzaldehyde, C6H5CHO (8), contributes to the characteristic aroma of cherries and almonds. Cinnamaldehvde (9) is found in cinnamon, and vanilla extract contains vanillin (10), which is present in oil of vanilla. Ketones can also be fragrant. For example, carvone (Section 18.1) is the essential oil of spearmint. 

The determination of aldehydes and ketones is of importance in the analysis of those essential oils characterised especially by aldehydic or ketoruc principles, e g.,the citral contained in lemon and lemongrass oils, citronellal in citronella Oil and some eucalyptus oils, benzaldehyde in bitter almond oil, salicylaldehyde in meadow-sweet oil, anisaldehyde in aniseed and fennel oils, cuminaldehyde m cumin oil, cinnamaldehyde in cinnamon oil, carvone in caraway oil, pulegone in pennyroyal oil and methyl nonyl ketone in rue oil The determination of the aldehydes and ketones presents, however, difficulties and the above methods are moderately exact in only a few cases, especially when the content of aldehydes or ketones is considerable The bisulphite method is applicable particularly to the determination of cinnamaldehyde and benzaldehyde in cinnamon oil and bitter almond oil, and, up to a certain pomt, to that of citral in lemongrass Oil. The sulphite method gives good results in the same cases and for the determination of carvone and pulegone... 

Table II lists 13 of the most commonly-used chemicals in the flavor industry. For example, cinnamic aldehyde is used for the generation of cassia or cinnamon flavors, carvone for spearmint flavors, citral for citrus flavors, and benzaldehyde for cherry flavors. As can be seen, the known s values for these compounds are...

Many other ketones and aldehydes are used as flavorings and additives to foods, drugs, and other products. For example, benzaldehyde is the primary component of almond extract, and (- )-carvone gives spearmint chewing gum its minty flavor. Table 18-4 lists some simple ketones and aldehydes with well-known odors and flavors. Pyrethrin, isolated frompyrethrum flowers, is commercially extracted for use as a natural insecticide. Natural or not, pyrethrin can cause severe allergic reactions, nausea, vomiting, and other toxic effects in animals. 

Both simple carbonyl compounds and a,j8-unsaturated ketones react with this reagent with exclusive formation of epoxides (oxiranes), not cyclopropanes. Yields are as follows benzaldehyde, 75% cycloheptanone, 97% benzalacetophenone, 87% carvone, 89% eucarvone, 93% pulegone, 90% A -cholestene-3-one, 90%. 

Recently, several sulfides with a bicyclo[3.2.1] framework have been developed for the ylide epoxidation reaction. In 2008, Metzner and coworkers prepared several bridged sulfides starting from (R)-carvone, which were then evaluated in the epoxidation of benzaldehyde with benzyl bromide (Scheme 20.8). Sulfide 12 was found to be the most enantioselective, delivering the desired trans epoxide in 54% yield and 84% ee in 4 days. Sulfide 15, which was prepared from 12 by reacting with PhLi followed by dehydration, is much more reactive than 12, providing 80% yield in one day but the enantioselectivity was lower (55% ee) [19]. 

---