Thionyl Chloride → 3-Methyl-2-cyclopentene-1-acetic acid
Reaktionsgleichung
C12CC(CC1)C[CH2:3][O:2]2.[CH3:9][C:10]1[CH2:14][CH2:13][CH:12]([C:15](O)=O)[CH:11]=1.S(Cl)(Cl)=[O:19]>>[CH3:9][C:10]1[CH2:14][CH2:13][CH:12]([CH2:15][C:3]([OH:2])=[O:19])[CH:11]=1Komponenten
4
Versuchsvorschrift
When m is 0, n is 2 and p is 2, the ring system is a 2-oxabicyclo[3.2.1]octane, another subclass of this invention. For example, compound XIp, ##STR25## in which R2, R5 and R6 are methyl, can be prepared by conversion of 3-methylcyclopent-2-ene-1-carboxylic acid described in IV to the corresponding acid chloride with thionyl chloride. The resulting carboxylic acid chloride is subjected to a modified Arndt-Eistert homologation, as described by G. P. Kugatova-Sheinyakina and R. A. Poskiene, Zh. Organ. Khim., 2(5), 844 (1966) (CA 65 10504c) to produce 3-methyl-2-cyclopentene-1-acetic acid, which is treated similarly to the acid of Subclass IX to yield the desired 2-oxabicyclo[3.2.1]octan-8-ol. The octanol is treated with WCH2X in which X is halogen to yield the desired ether, XIp.