Reaktion #87949

Reaktionsgleichung

methyl cis-(1aRS,7bSR)-1,1-dibromo-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Intermediate 8

methyl cis-(1aRS,7bSR)-1,1-dibromo-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

ammonium chloride

ammonium chloride

→

methyl cis-(1aRS,7bSR)-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Ausbeute 97.2%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturat reflux for 6 hours
3. 3
   workup.STIRRINGthe mixture was stirred
4. 4
   Temperaturheated
5. 5
   Temperaturat reflux overnight
6. 6
   TemperaturAfter cooling
7. 7
   Filtrationthe mixture was filtered through Celite
8. 8
   Sonstigethe filtrate was evaporated to dryness
9. 9
   SonstigeThe residue was partitioned between DCM and water
10. 10
    Trocknenthe organic layer was dried (MgSO4)
11. 11
    Filtrationfiltered
12. 12
    SonstigeThe filtrate was evaporated to dryness

Vorschrift

A mixture of methyl cis-(1aRS,7bSR)-1,1-dibromo-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (Intermediate 8, 1.06 g), zinc dust (4.14 g), and ammonium chloride (1.75 g) in absolute ethanol (100 mL) was stirred and heated at reflux for 6 hours. Further zinc dust (2.0 g) and ammonium chloride (0.9 g) were added and the mixture was stirred and heated at reflux overnight. After cooling, the mixture was filtered through Celite and the filtrate was evaporated to dryness. The residue was partitioned between DCM and water and the organic layer was dried (MgSO4) and filtered. The filtrate was evaporated to dryness to give methyl cis-(1aRS,7bSR)-5-methoxymethyl-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.63 g) as an oil.

Quelle