Para-Methoxybenzyl

When Ry was n-butyl, phenyl, benzyl or para-methoxybenzyl, the products obtained were from path B ... 

GABA HMG-CoA HMPA HT LDA LHMDS LTMP NADH NBH NBS NCS NIS NK NMP PMB PPA RaNi Red-Al RNA SEM SnAt TBAF TBDMS TBS Tf TFA TFP THF TIPS TMEDA TMG TMP TMS Tol-BINAP TTF y-aminobutyric acid hydroxymethylglutaryl coenzyme A hexamethylphosphoric triamide hydroxytryptamine (serotonin) lithium diisopropylamide lithium hexamethyldisilazane lithium 2,2,6,6-tetramethylpiperidine reduced nicotinamide adenine dinucleotide l,3-dibromo-5,5-dimethylhydantoin A-bromosuccinimide A-chlorosuccinimide A-iodosuccinimide neurokinin 1 -methyl-2-pyrrolidinone para-methoxybenzyl polyphosphoric acid Raney Nickel sodium bis(2-methoxyethoxy)aluminum hydride ribonucleic acid 2-(trimethylsilyl)ethoxymethyl nucleophilic substitution on an aromatic ring tetrabutylammonium fluoride tert-butyldimcthyisilyl fert-butyldimethylsilyl trifluoromethanesulfonyl (triflyl) trifluoroacetic acid tri-o-furylphosphine tetrahydrofuran triisopropylsilyl A, N,N ,N -tetramethy lethylenediamine tetramethyl guanidine tetramethylpiperidine trimethylsilyl 2,2 -bis(di-p-tolylphosphino)-l,r-binaphthyl tetrathiafulvalene... 

De Armas and co-workers [67] chose the epoxide 122, a derivative of D-mannose, as their starting material for what they claim a formal synthesis of (+)-preussin (Scheme 30, PMB=para-methoxybenzyl). In 14 steps and 8%... 

The para-methoxybenzyl group belongs to a class of alcohol protecting groups that are stable to basic conditions but can be removed by oxidation. Here DDQ (2,3-dichloro-5,6-dicyano-l,4-benzoquinone) is used to yield the free primary alcohol 3. 

Hydrogenolysis of para-methoxybenzyl ether was made on 10% Pd/C in EtOH under a hydrogen atmosphere. 

In this section, the formation and cleavage of eight protecting groups for alcohols and phenols are presented acetate acetonides for diols benzyl ether para-methoxybenzyl (PMB) ether methyl ether methoxymethylene (MOM) ether ferf-butyldiphenylsilyl (TBDPS) silyl ether and tetrahydropyran (THP). 

Estimated at 20°C from the temperature dependence of the Hammett p value for the para-nitrobenzyl chloride reaction. The p value for the para-methoxybenzyl chloride reaction measured at 0°C was-0.26. rfThe error in the individual KIE is +0.00015. 

The predominant property of these salts is the ease with which nucleophiles add to the quinolinium-2-and the isoquinolinium-1-positions. Such additions are favoured in these bicyclic compounds since the products retain a complete aromatic benzene ring. Hydroxide, hydride and organometaUic nucleophiles aU add with facility, though the resulting dihydroaromatic products require careful handling if they are not to disproportionate or be oxidised. " This approach can give 2-nifluoromethyl-quinolines CFj carbanion (from trifluoro(trimethylsilyl)methane and fluoride) is added to an A -(para-methoxybenzyl)-quinolinium salt, then the A -substituent is removed and oxidation to the aromatic level achieved with ceric ammonium nitrate. ... 

A. Kikkawa, T. Takata, and T. Endo, Cationic polymerization of vinyl monomers with latent initiators. 3. l-(Para-methoxybenzyl)tetrahydrothiophenium hexafluoroantimonate as a new potent cationic initiator. Makromol. Chem. Macromol. Chem. Phys. 1991,192(3), 655-662. 

We often observed such elimination of silyl alcohol or para-methoxybenzyl alcohol, especially from beta hydroxyl protected aldehydes. Attempts to convert all of 17 into 18 were unsuccessful. The final reaction conditions were a compromise to minimize by-product formation. Aldehyde 18 is stable if stored at < -10 °C. 

In terms of electronic tuning, it has been mentioned already that electron-donating phenyl substituents confer increased lability towards oxidizing agents, and para-methoxybenzyl (PMB) ethers—introduced by methods analogous to those used for the benzyl group—are routinely employed because they can be removed highly... 

---