Patent GB-784893-A (GB)
Title: Improvements in or relating to the use of certain methyl-irone isomers in perfumes
IPC: C11B9/00
Filed: 1955-09-20
Abstract: The invention comprises a perfume constituted by the stereoisomer of 22-methyl-a -irone the semicarbazone of which melts at 188-189 DEG C., and a mixture of 22-methyl-a -irones containing at least to 20 per cent of that isomer.  This isomer, together with other isomers, is obtained by subjecting to cyclization with boron trifluoride a technical mixture of stereoisomer 9-methyl-pseudoirones containing no, or only a minor proportion, of 11-methyl-pseudoirones as in Specification 666,881 and 666,993.  The isomer may be separated wholly or partially from other isomers by distillation or through a crystalline derivative such as a semi-carbazone.  The isomer may be mixed with other substances, e.g. the a -irone preparations according to Swiss Specification 276,421, vertevert oil, extracts of odorous plants containing coumarin, extracts prepared from oak moss, ambergris, vanilla pods.  In examples, a crude mixture of 9-methyl pseudoirones is obtained by heating 3-methyl-dehydrolinalool (i.e. [3,4-dimetho-3-pentene-yl]-methyl - ethynyl - carbinol) with ethyl a -methyl acetoacetate, the crude mixture was cyclized with boron trifluoride, and the isomers separated by distillation or through the semicarbazones.  Further examples describe compositions comprising the above 22-methyl-a -irone isomer the semicarbazone of which melts at 188-189 DEG  C. together with (a) 22-methyl-a -ionone, a -ionone, a -irone, ylang-ylang oil, hydroxy citronellal, methylnonylacetic aldehyde, lauric aldehyde and methyl heptine carbonate; and (b) lavender oil, bergamot oil, sweet orange oil, pressed lemon oil, Bulgarian rose oil, clove oil, rhodinol, a -irone, phenyl ethyl valerianate, coumarin, tonka bean absolute, and vanilla extract.ALSO:The invention comprises a perfume constituted by the stereoisomer of 22-methyl-a -irone, the semicarbazone of which melts at 188-189 DEG  C., and a mixture of 22-methyl-a -irones containing at least 20 per cent of that isomer.  This isomer, together with other isomers, is obtained by subjecting to cyclisation with boron trifluoride a technical mixture of stereo-isomer 9-methyl-pseudoirones containing no, or only a minor proportion, of 11-methyl-pseudoirones as in Specifications 666,881 and 666,993, [both in Group IV (b)].  The isomer may be separated wholly or partially from other isomers by distillation or through a crystalline derivative such as semi-carbazone.  The isomer may be mixed with other substances, e.g. the a -irone preparations according to Swiss Specification 276,421, vetevert oil, extracts of odourous plants containing coumarin, extracts prepared from oak moss, ambergis, vanilla pods. In examples, a crude mixture of 9-methyl pseudoirones is obtained by heating 3 - methyl - dehydrolinalool (i.e. [3.4 - dimetho-3 - pentene - yl] - methyl - ethynyl - carbinol) with ethyl a -methyl acetoacetate, the crude mixture was cyclized with boron trifluoride, and the isomers separated by distillation or through the semi-carbazones.  Further examples describe compositions comprising the above 22-methyl-a -irone isomer, the semi-carbazone of which melts at 188-189 DEG  C., together with (a) 22-methyl-a -ionone, a -ionone, a -irone, ylang-ylang oil, hydroxy citronellal, methylnonylacetic aldehyde, lauric aldehyde and methyl heptine carbonate, and (b) lavender oil, bergamot oil, sweet orange oil, pressed lemon oil, Bulgarian rose oil, clove oil, rhodinol, a -irone, phenyl ethyl valerianate, coumarin, tonka bean absolute, and vanilla extract.