Preparation of polycyclic ethers

Abstract

Process for the preparation of polycyclic ethers of formula ##STR1## wherein X represents --(CH.sub.2).sub.n --, index n stands for integer 0 or 1, symbol R.sup.4 designates a hydrogen atom or a methyl radical, symbols R.sup.1 and R.sup.2, identical or different, represent each a hydrogen atom or a lower alkyl radical from C.sub.1 to C.sub.3 and R designates either a C.sub.1 to C.sub.6 linear or branched alkyl radical, or a substituted or unsubstituted alkenyl radical having 2 or 3 carbon atoms in the main chain, said alkenyl radical forming a ring such as indicated by the dotted line, which process comprises the cyclization by means of an acidic agent of an unsaturated compound: a) of formula ##STR2## having a double bond in one of the positions indicated by the dotted lines, and wherein index m defines an integer number equal to 1 or 2, symbol R.sup.3 stands for a hydrogen atom or a protecting group of the hydroxyl function bound to the oxygen atom and able to dissociate itself from the latter under the reaction conditions, the wavy line represents a C--C bond of cis or trans configuration and index n and symbols R, R.sup.2 and R.sup.4 are defined as above; or b) of formula ##STR3## wherein symbols R.sup.2, R.sup.3 and R.sup.4, index n and the wavy line are defined as above; or c) of formula ##STR4## wherein symbols, R.sup.2, R.sup.3 and R.sup.4, index n and the wavy line are defined as above. Some of the compounds (I) are novel and can be used in the perfume industry.

Dependencies are inferred from the claim text.