1 -Methoxy-2-methyl-1 -

Ethoxycarbonyl-5-methoxy-4-methyl- E8a, 928 [ROOC - CH(CH3) - NH -CO-COOR + cocy... 

Methoxy-4-methyl- -methylester E19a, 807 (Alkohol + En/- - En) 1-Hexen 4-Hydroxy-3-(methoxy-methoxy)-5-methyl- E21b, 1427 [RO CH = CH —CH2 B(OR)2 + (H3C)2CH-CHO] Kohlensaure -bis-[2-methyl-propyl-ester] E4, 77 (Umester.) Nonansanre 2-Hydroxy- VI/la,l, 109... 

Jacobi s group cyclodehydrated iV-carbobenzyloxy-D-prolyl-L-alanine methyl ester 438 using POCVpyridine to prepare large quantities (50 g) of the 5-methoxy-4-methyl-2-substituted oxazole 439 (Scheme 1.121). Both 439 and ent-439 were key starting points for their enantiospecific syntheses of (+)-norsecurinine and (—)-norsecurinine. 

To 4 mL glacial acetic acid there was added 1.0 g 5-methoxy-4-methyl-2-(methylthio)benzaldehyde, 0.35 g anhydrous ammonium acetate, and 0.8 g nitroethane, and the mixture was heated on the steam bath for 4 h. Another 0.5 g of nitroethane was added, and the heating continued for an additional 4 h. Standing at room temperature overnight allowed the deposition of spectacular orange crystals which were removed by filtration, washed lightly with acetic acid, and air dried. This product melted at 82-83 deg C. 

Recrystallization from 10 mL boiling MeOH gave 0.7 g of 1-(5-methoxy-4-methyl-2-methylthiophenyl)-2-nitropropene with a mp of 83-84 deg C. Anal. (C12H15N03S) C,H. The alternate method for the formation of nitrostyrenes, the reaction of the benzaldehyde in nitroethane as both reagent and solvent, with ammonium acetate as a catalyst, gave a gummy product that could be purified only with severe losses. The overall yield with this latter method was 24% of theory. 

N 300 2,4,5-Trimethoxy-PEA T 65 4-Ethyl-5-methoxy-2-methylthio-A A 12-25 4-Ethyl-2-methoxy-5-methylthio-A U 4-Ethyl-2-methoxy-5-methylthio-PEA A 60-100 5-Methoxy-4-methyl-2-methylthio-A U 5-Methoxy-4-methyl-2-methylthio-PEA A 30-50 2-Methoxy-4-methyl-5-methylthio-A U 2-Methoxy-4-methyl-5-methylthio-PEA A 150 5-Methoxy-4-methyl-5-methylsulfinyl-A A 20-25 4-Propylthio-3,5-dimethoxy-PEA N 240 3,4,5-Triethoxy-PEA N 200 3-Ethoxy-5-ethylthio-4-methoxy-PEA N 240 3,5-Diethoxy-4-methylthio-PEA... 

Mycophenolic acid (6-[l,3-dihydro-7-hydroxy-5-methoxy-4-methyl-l-oxoisobenzofuran-6-yl]-4-methylhex-4-enoic acid) [24280-93-1] M 320.3, m 141°, 141-143°, pKe,ki) 2.5 (CO2H), pKE,t(2r9.5 (phenolic OH). 

A soln. of 1.7 eqs. 5-methoxy-4-methyl-2-phenyloxazole in benzene-d added via syringe to a soln. of thioacetaldehyde-cyclopentadiene adduct in the same solvent under N2, the mixture deaereated via 3 freeze-pump-thaw cycles at —78° to room temp., the tube sealed under vacuum, and heated to 135—40° for 48 h - 2-carbo-methoxy-2,5-dimethyl-4-phenyl-3-thiazoline. Y 85%. F.e. and photochemical method (from a-(alkylthio)acetophenones), also with thioacetone, s. E. Vedejs, S. Fields, J. Org. Chem. 53, 4663-7 (1988). 

Preparation by oxidation of 5-methoxy-6-methyl-2,3-di-phenylbenzofuran with chromium trioxide in refluxing acetic acid for 30 min, followed by alkaline hydrolysis of the resulting keto ester (2-benzoyloxy-5-methoxy-4-methyl-benzophenone) with potassium hydroxide in refluxing ethanol (75%) [752]. 

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