Publication Details (including relevant citation information):
Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (1994), (7), 859
Trans-5-Benzyloxy-3,4-dihydro-10-methoxy-1,3-dimethyl-1H-naphtho[2,3-c]pyran I (R = OCH2Ph, R1 = Me, R2 = H) and trans-3,4-dihydro-10-isopropoxy-7,9-dimethoxy-1,3-dimethyl-1H-naphtho[2,3-c]pyr an I (R = H, R1 = CHMe2, R2 = OMe) are formed with complete stereoselectivity by reaction of, resp., 2-allyl-1-benzyloxy-3-(1-hydroxyethyl)-4-methoxynaphthalene and the mixt. of (E)- and (Z)-3-(1-hydroxyethyl)-4-isopropoxy-5,7-dimethoxy-3-prop-2-enylnaphthalene with potassium tert-butoxide in DMF under nitrogen. The benzyloxy substituent of compd. I (R = OCH2Ph, R1 = Me, R2 = H) is removed in three steps to afford trans-3,4-dihydro-10-methoxy-1,3-dimethyl-1H-naphthop[2,3-c]pyran (II). II and I (R = H, R1 = CHMe2, R2 = OMe) are also transformed with complete stereoselectivity into the corresponding pseudoequatorial 4-alcs. III with potassium tert-butoxide in oxygenated DMSO and DMF, resp.
Address (URL): http://