摘要 |
<p>New substd. cyclopentenes are of formula (I): (where R1 to R6 are H, Me or Et, esp. H or Me). (I) are prepd. by cyclisation of 2-oxo-3,5,9-decatrienes of formula R2-CH2-C(=CHR1)-CHR3-CH2-C(CH2R4)=CH-CH=CR5 -CO-CH2-R6 (II), with concn., esp. 96-98%, H2SO4 at -40 to +20 degrees C. (I) are used as perfumery and flavouring synthetics, to impart hay and green, herbal notes in perfumes, cologne, soaps, foam baths and shampoos. (I) are esp. suitale for shaving lotions and shaving soaps. (I) may also be used for scenting detergents and other consumer articles and for flavouring food, drinks and tobacco. (I) can be prepd. in good yields. In an example a mixt. contg. 40% 4- 2,5,5-trimethyl-cyclopent-2-en-l-ylidene -butan-2-one and 60% 4- 2,5,5-trimethyl-cyclopent-1-en-1-yl -but-3-en-2-one. was prepd. in 58% yield by adding 6,9-dimethyl-3,5,9-decatriene-2-one to 96% H2SO4 and 100 ml hexane at -10 degrees C.</p> |