Claims
- 1. A process for preparing taxoid derivatives of formula II; ##STR12## wherein Ar represents an aryl radical,
- R.sub.1 represents a benzoyl radical or a radical R.sub.2 --O--CO-- in which
- R.sub.2 represents:
- a straight or branched alkyl radical containing 1 to 8 carbon atoms, an alkenyl radical containing 2 to 8 carbon atoms, an alkynyl radical containing 3 to 8 carbon atoms, a cycloalkyl radical containing 3 to 6 carbon atoms, a cycloalkenyl radical containing 4 to 6 carbon atoms, or a bicycloalkyl radical containing 7 to 11 carbons atoms, these radicals unsubstituted or substituted by at least one substituent selected from halogen atoms and hydroxyl radicals, alkyloxy radicals containing 1 to 4 carbon atoms, dialkylamino radicals in which each alkyl part contains 1 to 4 carbon atoms, piperidino radicals, morpholino radicals, 1-piperazinyl radicals (unsubstituted or substituted in the 4-position by an alkyl radical containing 1 to 4 carbon atoms or by a phenylalkyl radical in which the alkyl part contains 1 to 4 carbon atoms), cycloalkyl radicals containing 3 to 6 carbon atoms, cycloalkenyl radicals containing 4 to 6 carbon atoms, phenyl radicals, cyano radicals, carboxyl radicals, or alkoxycarbonyl radicals in which the alkyl part contains 1 to 4 carbon atoms;
- or by a phenyl radical unsubstituted or substituted by at least one atom or radical selected from halogen atoms, alkyl radicals containing 1 to 4 carbon atoms, or alkyloxy radicals containing 1 to 4 carbon atoms;
- or by a saturated or unsaturated heterocyclyl radical containing 4 to 6 members and unsubstituted or substituted by at least one alkyl radical containing 1 to 4 carbon atoms; and
- R.sub.3 represents:
- a straight or branched alkyl radical containing 1 to 8 carbon atoms, an alkenyl radical containing 2 to 8 carbon atoms, an alkynyl radical containing 3 to 8 carbon atoms, a cycloalkyl radical containing 3 to 6 carbon atoms, a cycloalkenyl radical containing 4 to 6 carbon atoms, or a bicycloalkyl radical containing 7 to 11 carbons atoms, these radicals unsubstituted or substituted by at least one substituent selected from halogen atoms and hydroxyl radicals, alkyloxy radicals containing 1 to 4 carbon atoms, dialkylamino radicals in which each alkyl part contains 1 to 4 carbon atoms, piperidino radicals, morpholino radicals, 1-piperazinyl radicals (unsubstituted or substituted in the 4-position by an alkyl radical containing 1 to 4 carbon atoms or by a phenylalkyl radical in which the alkyl part contains 1 to 4 carbon atoms), cycloalkyl radicals containing 3 to 6 carbon atoms, cycloalkenyl radicals containing 4 to 6 carbon atoms, or phenyl radicals, unsubstituted or substituted cyano radicals, carboxyl radicals, alkoxycarbonyl radicals in which the alkyl part contains 1 to 4 carbon atoms, or alkyl radicals containing 1 to 4 carbon atoms;
- or an aryl radical unsubstituted or substituted by at least one atom or radical selected from halogen atoms, alkyl radicals containing 1 to 4 carbon atoms, and alkyloxy radicals containing 1 to 4 carbon atoms, wherein R.sub.3 cannot represent an unsubstituted phenyl radical;
- or a saturated or unsaturated heterocyclyl radical containing 4 to 6 members and unsubstituted or substituted by at least one substituent selected from halogen atoms, alkyl radicals containing 1 to 4 carbon atoms, or alkoxy radicals of 1 to 4 carbon atoms;
- either R.sub.4 represents a hydrogen atom and R.sub.5 represents a protecting group of the hydroxyl functional group or R.sub.4 and R.sub.5 together form a saturated 5- or 6-membered heterocycl group,
- G.sub.1 represents a protecting group of the hydroxyl functional group, and
- G.sub.2 represents an acetyl radical or a protecting group of the hydroxyl functional group;
- comprising electrolytically reducing a product of formula VIII: ##STR13## wherein Ar and R.sub.1 are defined as above,
- R'.sub.5 represents a hydrogen atom or a protecting group of the hydroxyl functional group,
- R.sub.4 represents a hydrogen atom,
- G'.sub.1 represents a hydrogen atom or a protecting group of the hydroxyl functional group, and
- G'.sub.2 represents a hydrogen atom, an acetyl radical, or a protecting group of the hydroxyl functional group;
- wherein the electrolytic reduction is performed in an electrolyte comprising a quaternary ammonium salt which is soluble in an organic solvent or in an aqueous/organic mixture at a controlled potential.
- 2. A process of preparing a product of formula XI: ##STR14## wherein G.sub.1 represents a protecting group of the hydroxyl functional group, and
- G.sub.2 represents an acetyl radical or a protecting group of the hydroxyl functional group;
- comprising electrolytically reducing a product of formula XIII: ##STR15## wherein G'.sub.1 and G'.sub.2 are defined as above and G'.sub.3 represents a hydrogen atom or a protecting group of the hydroxyl functional group identical to G'.sub.1 ;
- wherein the electrolytic reduction is performed in an electrolyte comprising a quaternary ammonium salt which is soluble in an organic solvent or in an aqueous/organic mixture at a controlled potential, and then either the protecting group G'.sub.3 is selectively replaced by a hydrogen atom or the hydroxyl functional groups in the 7- and 10-positions are selectively protected.
- 3. The process according to claim 1 wherein
- either R.sub.5 represents a methoxymethyl, 1-ethoxyethyl, benzyloxymethyl, trimethylsilyl, triethylsilyl, (.beta.-trimethylsilylethoxy)methyl, or tetrahydropyranyl, or when R.sub.4 and R.sub.5 together form a heterocycyl group, said heterocycyl group is an oxazolidine ring unsubstituted or monosubstituted or gem-substituted in the 2-position,
- G.sub.1 represents a trialkylsilyl, dialkylsilyl, alkyldiarylsilyl, or triarylsilyl radical, wherein the alkyl portions contain 1-4 carbon atoms, and
- G.sub.2 represents an alkoxyacetyl radical.
- 4. The method according to claim 3 wherein the aryl portions of the G.sub.1 radicals are phenyl radicals.
Priority Claims (1)
Number |
Date |
Country |
Kind |
93 02370 |
Mar 1993 |
FRX |
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Parent Case Info
This is a division of application Ser. No. 08/204,128, filed Mar. 2, 1994 now U.S. Pat. No. 5,556,877.
US Referenced Citations (2)
Foreign Referenced Citations (1)
Number |
Date |
Country |
WO9417052 |
Aug 1994 |
WOX |
Divisions (1)
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Number |
Date |
Country |
Parent |
204128 |
Mar 1994 |
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