74383-55-4

Upstream product

• 74383-57-6 (R)-3-(3-acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho<2,3-b>furan-2-one 
• 74383-58-7 (R)-2,3-dihydro-3-(3-iodopropyl)-7-isopropyl-3,4-dimethylnaphtho<2,3-b>furan-2-one 
• 74383-56-5 (R)-2,3-dihydro-3-(3-hydroxypropyl)-7-isopropyl-3,4-dimethylnaphtho<2,3-b>furan-2-one 
• 74383-48-5 Δ⁶-6-hydroxy-5βH-dehydroabietic acid (18-6)-lactone 
• 18492-76-7 methyl (1R,4aS,10aR)-1,2,3,4,4a,10a-hexahydro-1,4a-dimethyl-7-(1-methylethyl)phenanthrene-1-carboxylate 
• 108-88-3 toluene 
• 98-59-9 p-toluenesulfonyl chloride 
• 104-15-4 toluene-4-sulfonic acid 
• 74383-53-2 bis<3-(2,3-dihydro-7-isopropyl-3,4-dimethyl-2-oxonaphtho<2,3-b>furan-3-yl)propyl> ether 

Relevant academic research and scientific papers

The C(1)-C(10) Bond Cleavage and B Ring Aromatization of Some 6-Hydrpoxy-5βH-abieta-6,8,11,13-tetraen-18-oic Acid 18,6-Lactones

Fusion of 6-hydroxy-5βH-abieta-6,8,11,13-tetraen-18-oic acid 18,6-lactone (2) with potassium hydrogensulfate at 220 deg C afforded bisfuran-3-yl)propyl> ether (12) in 37percent yield, together with two minor products in 12percent yield: 2,3-dihydro-7-isopropyl-3,4-dimethyl-3-propylnaphthofuran-2-one and 3-allyl-2,3-dihydro-7-isopropyl-3,4-dimethylnaphthofuran-2-one.Treatment of 12 with p-toluenesulfonic acid at 160 deg C gave 2,3-dihydro-7-isopropyl-3,4-dimethyl-3-(3-tosyloxypropyl)naphthofuran-2-one, which was converted into 2,3-dihydro-3-(3-hydroxypropyl)-7-isopropyl-3,4-dimethylnaphthofuran-2-one (16).The alcohol 16 was further characterized as its acetate (17).After several attempts, the above C(1)-C(10) bond cleavage and B ring aromatization reaction were improved by use of concentrated sulfuric acid in refluxing acetic acid.Under this conditions, 2 gave 17 in 47percent yield.Hydrolysis of 17 with hydrochloric acid afforded 16.Subsequently, 12-hydroxy-, 12-methoxy-, 12-acetoxy-, and 12-nitro-6-hydroxy-5βH-abieta-6,8,11,13-tetraen-18-oic acid 18,6-lactones were each refluxed with concentrated sulfuric acid in acetic acid to give 6-hydroxy-, 6-methoxy-, 6-acetoxy-, and 6-nitro-3-(3-acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphthofuran-2-ones, respectively.From the present study, the 12-acetoxy derivative seems to be a suitable intermediate for the synthesis of coleon A.

FORMATION OF COLEON A SKELETON FROM (-)-ABIETIC ACID

By the treatment of Δ6-6-hydroxy-5βH-dehydroabietic acid (18-6)-lactone with potassium hydrogensulfate or conc. sulfuric acid, the B ring aromatization and the C1-C10 bond cleavage occurred to give 1,10-secoabietane derivatives possessing coleon A skeleton.