Functionalization of (R)-3-(3-Acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one and Some Related Compounds

Oxidation of (R)-3-(3-acetoxypropyl)-2,3-dihydro-6-hydroxy-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one with Fremy’s radical afforded the corresponding o-quinone, which was converted into (R)-5,6,8-triacetoxy-3-(3-acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one and its 5,6,9-triacetoxy isomer. (R)-3-(3-Acetoxypropyl)-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one was also converted into (R)-9-acetoxy- and (R)-5,8,9-triacetoxy-2,3-dihydro-7-isopropyl-3-(3-methoxypropyl)-3,4-dimethylnaphtho[2,3-b]-furan-2-one. Transformation of (R)-2,3-dihydro-6-hydroxy-3-(3-hydroxypropyl)-7-isopropyl-3,4-dimethylnaphtho-[2,3-b]furan-2-one into (R)-6-acetoxy-3-allyl-2,3-dihydro-7-isopropyl-3,4-dimethylnaphtho[2,3-b]furan-2-one was also achieved.