9.10- Dimethoxy-2-hydroxy-6,7- dihydro

Dimethoxy-4-hydroxy-dihydro cinnamyl alcohol (dihydrosynapic alcohol) 3-Methoxy-4-hydroxycinnamaldehyde (coniferaldehyde)... 

Benzo[b]furan, 2,3-dihydro-2-phenyl-synthesis, 4, 697 Benzo[b]furan, 2,3-dihydroxy-tautomerism, 4, 37 Benzo[6]furan, 4,6-dimethoxy-acylation, 4, 606 Benzo[6]furan, 2,3-dimethyl-acetylation, 4, 606 bromination, 4, 605 photooxygenation, 4, 642 Benzo[b]furan, 5,6-dimethyl-2,3-diphenyl-applications, 4, 709 Benzo[b]furan, 1,3-diphenyl-vertical ionization potential, 4, 587 Benzo[b]furan, 2-ethoxy-5-hydroxy-synthesis, 4, 127... 

Furan, 2,5-di hydro-2,5-dimethoxy- C NMR, 4, 573 heat of hydrogenation, 4, 592 Furan, 2,5-dihydro-3,4-dimethylene- H NMR, 4, 577 Furan, 2,3-dihydro-3-hydroxy-synthesis, 4, 685 Furan, 2,3-dihydro-5-lithio- C NMR, 4, 572 Furan, 2,3-dihydro-3-methyl- H NMR, 4, 570... 

Dimethoxy-3-(2-hydroxy-athyl)-2,3-dihydro-aus 5,6-Dimethoxy-2-oxo-3-(athoxycarbonyl-methyl)-2,3-dihydro-indol und Lithiumalanat 250... 

Photolytic cleavage (at 320nm) of the substituent at position 1 of 9-cyclopropyl-l-[(4,5-dimethoxy-2-nitrophenyl)-methoxycarbonyl-3-fluoro-2,6-dioxo-l,2-dihydro-6//-pyrido[l,2-tf]pyrimidine-7-carboxylate gave 9-cyclopropyl-3-fluoro-2-hydroxy-6-oxo-6//-pyrido[ 1,2-tf]pyrimidin-7-carboxylate <1995WO95/010519, 1996WO96/039407,... 

Dagegen tritt bei 2-Amino-4,5-diphenyl-4-hydroxy-4H-imidazol keine Umlagerung ein, da kei-ne Methyl-Gruppe vorhanden ist. Es wird stattdessen in konz. Salzsaure zu 2-Amino-4,5-di-hydroxy-4,5-diphenyl-4,5-dihydro-imidazol hydratisiert129. Mit Methanol/Salzsaure erhalt man 2-Amino-4,5-dimethoxy-4,5-diphenyl-4,5-dihydro-imidazol129 ... 

Mit 1-Amino-propan erhalt man analog das 13-Methyl-9-propylamirw-2,3,IQ-trimethoxy-5,6-dihydro-(dibenzo aig]chinolizinium)-chlorid mit Pyrrolidin und einigen anderen Ami-nen verlauft die Reaktion anders. N-Methyl-papaverinium-jodid laBt sich mil 2-Amino-ethanol, wie oben beschrieben, unter Austausch nur einer Methoxy-Gruppe in l-(3,4-Dimethoxy-benzyl)-6-(2-hydroxy-ethylamino)-7-methoxy-2-methyl-isochmolinium-jodid (90%) uberfiihren1. 

Catalytic hydrogenation of 3,4-dihydro-2//-pyrimido[2,l-a]isoquinoline-2,4-diones (93) and 3,3-diethyl-9,10-dimethoxy-3,4,6,7-tetrahydro-2//-pyrimido[2,l-a]isoquinoline-2,4-dione (94) over Pt02 and Pd/C catalysts gave l,3,4,6,7,llb-hexahydro-2/7-pyrimido[2,l-a]isoquinoline-2,4-diones (95) [69YZ649 71JPP71/09466]. From the mother liquid of compounds 93 (R = H, R1 = Et and R = R1 = Et) 3-ethyl-2-hydroxy-6,7-dihydro-and -8,9,10,1 l-tetrahydro-4//-pyrimido[2,l-a]isoquinolin-4-ones, and 3,3-diethyl-l,3,4,llb-tetrahydro-2//-pyrimido[2,l-a]isoquinoline-2,4-dione, also could be isolated as minor products. Reduction of 3,3-diethyl-l,3,4,6,7,llfo-hexahydro-2//-pyrimido[2,l-a]isoquinoline-2,4-dione (95, R = R1 = Et, R2 = H) with LAH in tetrahydrofuran at 70°C for 9 h afforded 3,3-diethyl-l,3,4,6,7,llb-hexahydro-2//-pyrimido[2,l-a]isoquinoline (96). 

Another general approach to sugars starts from (2-furyl)methanols (furfuryl alcohols, 22). Bromination at low temperature in methanol (Clauson-Kaas reaction) and subsequent mild acidic hydrolysis of 2,5-dimethoxy-2,5-dihydrofurans 23 obtained, leads to 6-hydroxy-2,3-dihydro-6//-pyran-3-ones 24 (Scheme 8) [40], The same dihydropyranones can be... 

Amino-4-hydroxy-8-methyl- E19d, 689 (aus 1,3-Oxazol-Der.) 7-Aminoxy-4-methyl- El 6a, 264 Furan 3,4-Dihydroxy-5-imino-2-phenyl-2,5-dihydro- VI/2, 698 Glyoxylsaure (3,4-Dimethoxy-phenyl)- -nitril E13/2, 1158 (Alkohol - Keton)... 

Benzoesaure 2-Hydroxy-5-(3-oxo-butanoylamino)- XI/2, 20 2-Benzofuran 6,7-Dimethoxy-3-nitromethyl-1-oxo-1,3-dihydro-VI/2, 576 Bernsteinsanre Benzoylamino- IV/lb, 644 2-(2-Hydroxy-benzylidenamino)- XI/ 2, 327... 

Hy droxy-ethyl)-5-i sopropyl-3,6-dimethoxy-2,5-dihydro- E21b, 1772 [2-H - 2-CH(OH)-Ar] 2-(l-Hydroxy-ethyl)-5-isopropyl-3,6-dimethoxy-3,6-dihydro- E21b, 1770 [H CH(OH)-CH3]... 

H-l,4-Benzoxazine 2,3-Dimethoxy-carbonyl-4-hydroxy-6-methyl-E9a, 145 (1,2-Benzoquinon-oxim/ Cu + ROOC-C = C —COOR) Kohtensaure tert.-Butylperoxyes.ter-phthalimidoester E13/1, 255 (C-Cl -> C-O-OR) 1,2-Oxazol rro i-3,5-Dimethoxycar-bonyl-4-phenyl-4,5-dihydro- -2-oxid E14b, 927 (R-N02 + R-CHO)... 

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