title: Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.
abstract: 3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.
authors.affiliation: Education Center, Faculty of Engineering, Chiba Institute of Technology, Chiba, Japan.
authors.forename: Yohko
authors.initials: Y
authors.lastname: Hanzawa
authors.forename: Kahoko
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kasashima
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Mino
authors.forename: Masami
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Fujita
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D004951:Esterification; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D004987:Ethers / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry*
chemical_list: D000438:Alcohols; D002264:Carboxylic Acids; D004952:Esters; D004987:Ethers; D007659:Ketones; D011714:Pyrans; C029750:methylheptenone