title: A green and sustainable approach: celebrating the 30th anniversary of the asymmetric l-menthol process.
abstract: Takasago has been devoted to producing l-menthol since 1954, and our long history of manufacturing this important aroma chemical is reviewed here. The current asymmetric catalytic process had its 30th anniversary in 2013. Our l-menthol process is considered carbon-neutral, and, therefore, 'green' and sustainable. It uses renewable myrcene obtained from gum rosin as a starting material. In addition, the Rh-BINAP (=2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) catalytic system is highly efficient. This pathway not only leads l-menthol, but a variety of 100% biobased aroma chemical products as well. By measuring the (14) C levels in a material, one can determine the percentage of carbon that is biobased. This biobased assay, described as the ratio plant-derived C/fossil-derived C, can clarify how renewable a product really is. This will be highlighted for several of Takasago's key aroma chemicals.
authors.affiliation: Takasago International Corporation, Corporate Research and Development Division 4 - 11, 1-Chome, Nishi-yawata, Hiratsuka City, Kanagawa 254-0073, Japan, (phone: +81-463-252000; fax: +81-463-252084). makoto_emura@takasago.com.
authors.forename: Makoto
authors.initials: M
authors.lastname: Emura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsuda
mesh_terms: D002384:Catalysis; D008610:Menthol / Q000138:chemical synthesis / Q000737:chemistry; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D008610:Menthol
keywords: Asymmetric synthesis; Catalysis; l-Menthol