Abstract: A process for the manufacture of .alpha.,.beta.,.gamma.,.delta.-unsaturated esters containing a very high proportion of the 4(Z)-isomer, which are valuable perfume and flavor materials. The .alpha.,.beta.,.gamma.,.delta.-unsaturated esters are manufactured by a Wittig synthesis from phosphoranes and fumaraldehyde-acid esters under specific conditions.

Abstract: New 12-alkoxy-3,7,11-trimethyl-dodecatetraenes are of interest as perfume and flavor materials having a mandarin and orange effect.The new compounds can be manufactured relatively simply, e.g. by vinylating or ethynylating the corresponding new, but easily accessible, 7-alkoxy-6-methyl-hept-5-en-2-ones and subsequently partially hydrogenating the products, reacting the resulting allyl alcohols with acetoacetic acid esters or diketenes at an elevated temperature, again vinylating or ethynylating the alkoxyketones obtained, then partially hydrogenating the products, and eliminating water from the 12-alkoxy-3,7,11-trimethyl-3-hydroxy-dodecatrienes thus obtained.

Abstract: A process for the manufacture of 2,6,6-trimethyl-cyclo-hex-2-en-1-one by reacting 3-alkoxy-4-methyl-3-pentene or 3-alkoxy-4-methyl-2-pentene or a mixture of these compounds with acrolein, and reacting the resulting 2-alkoxy-2-ethyl-3,3-dimethyl-2,3-dihydro-4H-pyran with acids. The product is an intermediate for numerous syntheses of scents. Furthermore, a number of carotenoid syntheses are based on 2,6,6-trimethyl-cyclohex-2-en-1-one or its hydrogenation product, 2,6,6-trimethyl-cyclohexan-1-one.