3 -methoxyphenyl

Six protective groups for alcohols, which may be removed successively and selectively, have been listed by E.J. Corey (1972B). A hypothetical hexahydroxy compound with hydroxy groups 1 to 6 protected as (1) acetate, (2) 2,2,2-trichloroethyl carbonate, (3) benzyl ether, (4) dimethyl-t-butylsilyl ether, (5) 2-tetrahydropyranyl ether, and (6) methyl ether may be unmasked in that order by the reagents (1) KjCO, or NH, in CHjOH, (2) Zn in CHjOH or AcOH, (3) over Pd, (4) F", (5) wet acetic acid, and (6) BBrj. The groups may also be exposed to the same reagents in the order A 5, 2, 1, 3, 6. The (4-methoxyphenyl)methyl group (=MPM = p-methoxybenzyl, PMB) can be oxidized to a benzaldehyde derivative and thereby be removed at room temperature under neutral conditions (Y- Oikawa, 1982 R. Johansson, 1984 T. Fukuyama, 1985). 

Difunctional target molecules are generally easily disconnected in a re/ro-Michael type transform. As an example we have chosen a simple symmetrical molecule, namely 4-(4-methoxyphenyl)-2,6-heptanedione. Only p-anisaldehyde and two acetone equivalents are needed as starting materials. The antithesis scheme given helow is self-explanatory. The aldol condensation product must be synthesized first and then be reacted under controlled conditions with a second enolate (e.g. a silyl enolate plus TiCl4 or a lithium enolate), enamine (M. Pfau, 1979), or best with acetoacetic ester anion as acetone equivalents. 

The Diabrotica spp. com rootworm beetles are specifically attracted to a variety of plant-produced phenylpropanoids, eg, ( )-cinnamaldehyde [14371-10-9] for the southern com rootworm D. undecimpunctata howardr, ( )-cinnamyl alcohol [4407-36-7] for the northern com rootworm D. barberi and indole [120-72-9] for the western com rootworm, D. virgifera virgifera. Especially powerflil lures for these rootworm beetles are 2-(4-methoxyphenyl)ethanol for the northern com rootworm and 4-methoxycinnamaldehyde [71277-11-7] (177) for the western com bootworm. 

Isoquinolin-1 -one, 3-(4-methoxyphenyl)-1,2-dihydro-synthesis, 3, 685 Isoquinolin-l-one, 3-methylthio-synthesis, 2, 403 Isoquinolin-l-one, 3-thiomethyl-syn thesis... 

N-(4 Methoxyphenyl)-N-benzoyl-3-chloro-3-chloroantranlllc acid (4) 2 To ice cooled NaoEt (Irom 0 11 g Na and 10 mL ElOH) was added in rapid succession meltiyl 2 chloro 6 hydroxybenzoate 2 (0 86 g 4 7 mmol) and N (4 methoxyphenyl)benzimidyl chloride 1 (t 14 g 4 7 mmol) in EI2O (30 mL) The mixture was stirred vigorously and allowed to stand at rt tor 48 h The oily solid obtained alter evaporation was heated to 210 215°C lor 70 min under N2 The product was diluted with water (5 4 mL) ElOH (10 8 mL) and treated with 1 M NaOEt (5 4 mL) The mixture was relluxed lor 90 mm the solvent evaporated and the aqueous solution acldilied The dark oil was heated with NaOH (7 5 g) m EtOH (22 mL) Alter removal ol benzoic acid by exhaustive extraction with water the product was recrystallized Irom EtOH to give 0 36 g ol 4 (27 7%), mp 139 5 140 5°C... 

Dihydro-2(3H)-turanthlone (3).2 Butyrolaclone 1 (0 86 g. 10 mmoO and [2,4-bis(4-methoxyphenyl)-l, 3-dilhia 2,4-diphospheiane-2,4-disui(ide) 2 (2 02 g, 5 mmol) in PhMe (10 mL) were heated to reflux until no more starling malenal was detected (TLC or GC) After cooling, the solvent was stripped off and the mixture was punlied on silica gel using CH2CI2 as eluent to afford 3, mp 96-97 C... 

II. 5-Bis(4-methoxyphenyl)methyl Thioether RSCH(C6H4-4-OCH3)2 (Chart 7)... 

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