The silylation of forskolin (I) with tert-butyl-dimethylsilyl chloride and imidazole in DMF gives the protected compound (II), which is deacetylated with aqueous NaOH at room temperature, yielding (III). The acylation of (III) with 3-chloropropionyl chloride in pyridine-dichloromethane affords 1-O-(tert-butyl-dimethylsilyl)-7-O-(3-chloropropionyl)-7-deacetylforskolin (IV), which is treated with dimethylamine in dichloromethane to give the corresponding dimethylamino derivative (V). The desilylation of (V) with trifluoroacetic acid in methanol yields compound (VI), which is submitted to isomerization by means of NaOH in water - acetonitrile, affording 7-deacetyl-6-O-[3-(dimethylamino)propionyl]forskolin (VII). Finally, this compound is acetylated with acetyl chloride and pyridine.

The silylation of forskolin (I) with tert-butyl-dimethylsilyl chloride and imidazole in DMF gives the protected compound (II), which is deacetylated with aqueous NaOH at room temperature, yielding (III). The acylation of (III) with 3-chloropropionyl chloride in pyridine-dichloromethane affords 1-O-(tert-butyl-dimethylsilyl)-7-O-(3-chloropropionyl)-7-deacetylforskolin (IV), which is treated with dimethylamine in dichloromethane to give the corresponding dimethylamino derivative (V). The desilylation of (V) with trifluoroacetic acid in methanol yields compound (VI), which is submitted to isomerization by means of NaOH in water - acetonitrile, affording 7-deacetyl-6-O-[3-(dimethylamino)propionyl]forskolin (VII). Finally, this compound is acetylated with acetyl chloride and pyridine.

The silylation of forskolin (I) with tert-butyl-dimethylsilyl chloride and imidazole in DMF gives the protected compound (II), which is deacetylated with aqueous NaOH at room temperature, yielding (III). The acylation of (III) with 3-chloropropionyl chloride in pyridine-dichloromethane affords 1-O-(tert-butyl-dimethylsilyl)-7-O-(3-chloropropionyl)-7-deacetylforskolin (IV), which is treated with dimethylamine in dichloromethane to give the corresponding dimethylamino derivative (V). The desilylation of (V) with trifluoroacetic acid in methanol yields compound (VI), which is submitted to isomerization by means of NaOH in water - acetonitrile, affording 7-deacetyl-6-O-[3-(dimethylamino)propionyl]forskolin (VII). Finally, this compound is acetylated with acetyl chloride and pyridine.