Sulfuric Acid → HCID 21432376, compound

HRID 2399082Notes

Reaction equation

HRID 2399082 reaction equation
O=[C:2](C)CCC#CCCCCO.OS(O)(=O)=O.[O:18]=[C:19]([CH3:30])[CH2:20][CH2:21][C:22]#[C:23][CH2:24][CH2:25][CH2:26][C:27]([OH:29])=[O:28]>CO>[CH3:2][O:28][C:27](=[O:29])[CH2:26][CH2:25][CH2:24][C:23]#[C:22][CH2:21][CH2:20][C:19](=[O:18])[CH3:30]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 21432367HCID 21432367, compoundHCID 21432375HCID 21432375, compound

Product 1

HCID 21432376HCID 21432376, compound

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

The Heather synthesis of 2-(6-carboxy-2-cis-hexynyl)-cyclopentane-1,3,4-trione implicitly includes a process for preparing 9-oxo-5-decynoic acid (I; n=3, R=H). Table A provides a synopsis of that synthesis which consists of: first treating 2-methyl-2-(3-butynyl)-1,3-dioxolane, III, with lithium amide in liquid ammonia and then with 1-bromo-4-tetrahydropyranyloxybutane, IV, in tetrahydrofuran to obtain 2-methyl-2-(8-pyranyloxy-3-oxtynyl)-1,3-dioxolane, V; hydrozyling V to 9-oxo-5-decyn-1-ol, VI; oxidizing VI with Jones's reagent (CrO3, H2SO4) to 9-oxo-5-decynoic acid; esterifying the latter with methanol under acidic catalyss to obtain methyl-9-oxo-5-decynoate, VII; hydrogenating VII over Pd/BaSO4 (Lindlar's catalyst) in quinoline to get methyl 9-oxo-5-cis-decenoate, VIII; condensing VIII with diethyl oxalate in the presence of sodium ethoxide in ethanol to obtain 2-(6-carbomethoxy-2-cis-hexenyl)-5-(ethoxyalkyl)-cyclopentane-1,3,4-trione, IX; and hydrolyzing IX under acidic conditions to obtain 2-(6-carboxy-2-cis-hexenyl)-cyclopentane-1,3,4-trione (II: n=3: R= H).

Sources & evidence

ORD record
ord-86760efcb2ea499ab3c459d7be806dd6
Source dataset
uspto-grants-1977_05
Patent number
US04026911

Reaction notes

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