similarly to Referential example 1, 532.4 mg(2.09 mmol) of (1R,3R,3aS,4S,4aR,8aS,9aR)-4-hydroxymethyl-1-methoxy-3-methyl-dodecahydronaphtho[2,3-c]furan were mesylated with 486.0 μl(3 equivalents) of methanesulfonyl chloride, 1458.6 μl (5 equivalents) of triethylamine and 23.5 mg(0.1 equivalent) of 4-(dimethylamino)pyridine to obtain 687.5 mg of yellow oily O-mesyl form. Then, this was converted to phenylthio form with 348.1 mg(1.5 equivalents) of potassium t-butoxide and 318,5 μl (1.5 equivalents) of thiophenol and further oxidized with 1290.0 mg(2.5 equivalents) of m-chloroperbenzoic acid(70%) and 879.2 mg(5 equivalents) of sodium hydrogencarbonate to obtain 311.2 mg of (1R,3R,3aR,4S,4aR,8aS,9aR)-1-methoxy-3-methyl-4-(phenylsulfonyl)methyl-dodecahydronaphtho[2,3-c]furan(yield after 3 processes 39%).
