The new spirocyclic compounds of the general formula (I):
are powerful odorants.
In the formula the -C(O)X-substituted ring is saturated or unsaturated in the α or β position, and X represents a methylene group or an oxygen atom, R1, R2, R3, R4 are independently a hydrogen atom or a methyl radical, n or n' are independently 1 or 2 and R4 can be at any position on the ring not being the -C(O)X substituted ring.
A method of making spirogalbanone includes the steps of:
(a) subjecting ethynylspirodecanol to a Rupe rearrangement to give a compound of the formula I
(b) converting the compound of (a) to a C1-C4 alkyl acetal;
(c) subjecting the acetal to a trans-acetalization reaction with allyl alcohol in the presence of a mild acid catalyst;
(d) heating the product of (c) in the presence of an acid catalyst to give an allylenolether; and
(e) subjecting the product of (d) to a Claisen rearrangement to give spirogalbanone.
The method affords an easier and more efficient method of preparation.
A method of making spirogalbanone includes the steps of:
(a) subjecting ethynylspirodecanol to a Rupe rearrangement to give a compound of the formula I
(b) converting the compound of (a) to a C1-C4 alkyl acetal;
(c) subjecting the acetal to a trans-acetalisation reaction with allyl alcohol in the presence of a mild acid catalyst;
(d) heating the product of (c) in the presence of an acid catalyst to give an allylenolether; and
(e) subjecting the product of (d) to a Claisen rearrangement to give spirogalbanone.
The method affords an easier and more efficient method of preparation.