Olivetolic Acid concept correct?

[Idontcarethatmuch]

Hey
I need Olivetolic Acid so I can cycle it to thca (for beautiful diamonds) instead of olivetol > thc

So I tried to ask an AI to do modify the recipe of @halohidrin but I am not quite sure if this is right. Maybe someone of the chemist or even @halohidrin could look over it and confirm or give a change suggestion?

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Step-by-Step Procedure for Olivetolic Acid (Conceptual)​

Part 1: Linear Ketone-Ester Synthesis

• Prepare ketone solution: acetone + KOH in three-neck round-bottom flask, stir at ~30 °C.
• Prepare aldehyde solution: hexanal + terminal carboxylic ester in acetone.
• Slowly add aldehyde solution to ketone solution over 1 hour, maintain temperature at 30 °C.
• Let reaction proceed 100 min, adjust pH to 7 with phosphoric acid.
• Separate phases, collect organic layer, remove acetone by distillation.

Part 2: Alkene Formation

• Take product from Part 1, add water, adjust pH to 2 with phosphoric acid.
• Reflux for 2 h at mild temperature (do not exceed 80 °C).
• Extract three times with ethyl acetate, combine extracts, remove solvent.
• Vacuum distillation at ~62–65 °C under 3 mmHg.
• Result: linear ketone-ester with terminal carboxylic ester.

Part 3: Cyclization to Cyclic Ketone-Ester

• Prepare solution of sodium methoxide + dimethyl malonate in anhydrous methanol.
• Slowly add linear ketone-ester from Part 2 under nitrogen, stir under reflux for ~3 h.
• Distill off solvent, dissolve residue in water.
• Extract crystals with chloroform, acidify aqueous phase to pH 4 with HCl.
• Filter and dry → cyclic β-ketoester with terminal COOH preserved as ester.

Part 4: Aromatization to Olivetolic Acid

• Dissolve bromine in DMF, keep in ice bath.
• Keep cyclic ketone-ester from Part 3 cool in DMF, add bromine solution slowly (~90 min).
• Gradually warm to max 80 °C until aromatic ring formation is complete (COOH retained).
• Remove DMF, treat mixture with water.
• Extract with ether, wash combined layers with 10 % aqueous NaHSO₃ and 10 % aqueous acetic acid.
• Remove ether → viscous oil.
• Hydrolyze ester with NaOH/water to obtain free carboxylic acid.
• Neutralize with HCl → olivetolic acid precipitates, filter and dry.

​

Required Chemicals (with Function and Approximate Amounts)​

• Acetone – ketone source – 159 g
• KOH 10 % aq. – base for condensation – 200 mL
• n-Hexanal – aldehyde for chain elongation – 81.5 g
• Methylpropionate (or other terminal ester) – terminal carbon source – 20–25 g
• Dimethyl malonate – cyclization agent – 90 g
• Sodium methoxide (in methanol) – base for cyclization – 32.4 g
• Anhydrous methanol – solvent – 230 mL
• Bromine – aromatization/bromination – 37.9 g
• DMF – solvent – 115 mL
• NaOH – ester hydrolysis – ~1.1 equiv of ester
• Phosphoric acid – pH control – as needed
• Ether – extraction – 250 mL
• Chloroform – extraction – 80 mL
• HCl – acidification – as needed

THX A LOT

 

[bilibili]

We have tried various methods to synthesize olivetol，this method not only has a low yield, but also is difficult to obtain high-purity products.
So the same goes for synthesizing olivetolic acid. I suggest you don't do this，might waste a lot of time.

 

[Idontcarethatmuch]

So you have a good one for olivetol/olivetolicacid

 

[bilibili]

yes, our laboratory synthesized high-purity olivetol and 5-Heptylresorcinol.

 

[Idontcarethatmuch]

Why don't you share it this is what this community is for