Haouamine A:

 

 

 

 

 

 

 

Boron tribromide was added to Indeno-tetrahydropyridine in CH2Cl2 at -78°C. The solution was warmed to room temperature and stirred for 1.5 hours. Aqueous 1KH2PO2/K2PO4 was then added to the solution. The entire solution was then dried over 2MgSO4, concentrated and filtered. After this, anhydride and pyridine were added to the solution and the mixture was stirred at room temperature for 3h. The material then went through flash chromatography (silica gel, 4:1 hexanes:EtOAc) to give compound 15. The solution was then dissolved 3o-dichlorobenzene and 2,5-du-ter-butyl-4-methylphenol. The solution then irradiated in a microwave at 250°C for 10h. Once the solution cooled to room temperature it was passed through silica gel eluting first with hexanes to remove 3o-dichlorobenzene and subsequently with EtOAc. TLC was run (2:1 hexanes:EtOAc). The recovered compound, 15, and peracetyl haouamine A contaminated with it’s atropisomer were dissolved In 1:1 MeOH:CH2Cl2  and treated with potassium carbonate. The solution was stirred for 30 minutes, aqeous 1KH2PO4/K2PO4 was added. The aqueous layer of the solution was extracted with EtOAc (3 x 10 mL) in a separatory funnel. The combined organics were dried over 2MgSO4 and then filtered and concentrated. The resulting solution was purified by preparatory HPLC, which afforded the TFA salt of Haouamine A. The TFA salt was neutralized with aqueous 1KH2PO4/K2PO4 and then extracted with EtOAc (3 x 10 mL). The extracted organics were then dried over 2MgSO4, filtered, and concentrated to yield pure Haouamine A as a white film. 

Footnotes:

Flash Column Chromatography- A method used in chemistry to separate compounds with different polarities in the same molecule.

HPLC Chromatography- High-performance liquid chromatography is a form of column chromatography used frequently in biochemistry and analytical chemistry to separate, identify, and quantify compound

Microwave- Used to quickly provide a thermal source of energy to a reaction. For example in a diels-alder reaction some sort of thermal source needs to be present in order to excite the electrons allowing the two compounds to react.

 

KH2PO2/K2PO4 is used as the solotion in order to maintain a fairly low PH and maintain the protanated form of the titled compound

 

 

 

 

MgSO4 is a common drying reagent and aborbs the water produced by KH2PO2/K2PO4

 

 

 

 

A common chemical intermediate for plastics, dyes, pharmaceuticals and other organic compounds, which is insoluble in water.