Process for the preparation of vitamin K2

1. A process for the preparation of a compound of formula (I)

comprising a step in which (i) a compound of formula (II) is reacted with a compound of formula (III)

wherein R is an alkyl group;

LG is a leaving group;

m is an integer from 0 to 8;

n is an integer of from 0 to 9; and

X is hydrogen, halide, hydroxyl or protected hydroxyl;

in the presence of a palladium catalyst;

(ii) if necessary, converting X into a leaving group;

(iii) reacting with a compound (V) or (VI)

wherein Ar is aryl and m is independently as hereinbefore defined in the presence of a base;

(iv) reducing the —SO 2 Ar or SAr group in the resulting compound to a hydride; and

(v) converting the diprotected naphthoquinone into a naphthoquinone.

2. A process as claimed in claim 1 wherein step (v) is achieved using cerium ammonium nitrate (CAN).

3. A process as claimed in claim 1 wherein the reaction of a compound of formula (II) with a compound of formula (III) results in compound (I′) in which X is hydrogen

4. A process as claimed in claim 3 in which a terminal hydrogen (i.e. the hydrogen at the X position) is converted to hydroxyl using selenium dioxide and thereafter converted to a leaving group, e.g. a halide to thereby facilitate step (ii).

5. A process for the preparation of a compound of formula (I)

comprising a step in which (i) a compound of formula (II) is reacted with a compound of formula (III)

wherein R is an alkyl group;

LG is a leaving group;

m is an integer from 0 to 8;

n is an integer of from 0 to 9; and

X is hydrogen, halide, hydroxyl or protected hydroxyl;

in the presence of a palladium catalyst;

(ii) converting X into a SPh or —SO 2 Ph group to form compound (VII)

wherein m is independently as hereinbefore defined;

(iii) deprotonating (alpha to the sulphur) and reacting with a compound

wherein m is independently as hereinbefore defined;

(iv) reducing the phenylthioether or —SO 2 Ph to hydrogen; and

(v) converting the diprotected naphthoquinone into a naphthoquinone ring.

6. A process for the preparation of a compound of formula (I)

comprising a step in which (i) a compound of formula (II) is reacted with a compound of formula (III)

wherein R is an alkyl group;

LG is a leaving group;

m is an integer from 0 to 8;

n is an integer of from 0 to 9; and

X is hydrogen, halide, hydroxyl or protected hydroxyl;

in the presence of a palladium catalyst;

(ii) if necessary converting X into a leaving group;

(iii) reacting with a compound

wherein m is independently as hereinbefore defined;

in the presence of a Pd catalyst; and

(iv) converting the diprotected naphthoquinone into a naphthoquinone.

7. A process as described in claim 1 wherein the compound of formula (I) is MK-7