SYNTHESIS 2-methoxy-4 -methyl

Nucleophilic additions to (cyclohexadienone)Fe(CO)3 complexes (218) occur in a dia-stereospecific fashion (Scheme 56)197. For example, the Reformatsky reaction of ketone (218a) affords a simple diasteromeric alcohol product19715. The reduction of (1-carbo-methoxycyclohexa-l,3-dien-5-one)Fe(CO)3 (218b) to give 219 has been utilized in the enantioselective synthesis of methyl shikimate. In a similar fashion, cycloadditions of (2-methoxy-5-methylenecyclohexa-l,3-diene)Fe(CO)3 (220) occur in a diastereospecific fashion198. 

Natnre does not actually make a methylenedioxy group using formaldehyde. Instead, it modifies an existing ortAo-hydroxy-methoxy arrangement. Enzymic hydroxylation of the methoxy methyl converts this substitnent into what is identical to a hemiacetal of formaldehyde, and then acetal formation follows in a process analogous to a chemical synthesis. The hydroxylating enzyme involved is a cytochrome P-450 mono-oxygenase (see Box 11.4). 

Hydroboration was also employed"0 in the synthesis of methyl 2,3-dideoxy-4-0-methyl-a-DL-g/ /C(TO-pentopyranoside (182) from 3,4-di-hydro-2-methoxy-2H-pyran (181). Catalytic dealcoholation of 182 afforded 3,4-dihydro-3-methoxy-2f/-pyran (183), which, on bromination in methanol, gave"0 methyl 2-broino-2,3-dideoxy-4-0-methyl-a-DL-en/t/iro-pentopyranoside (184) as the main product. 

N. Hamamichi and T. Miyasaka, Synthesis of methyl- and methoxy-substituted [) n riba furanosylnaphthalene derivatives by Lewis acid catalyzed ribofuranosylation, J. Org. Chem. 56 3731 (1991). 

The synthesis of succinic acid derivatives, /3-alkoxy esters, and a,j3-unsaturated esters from olefins by palladium catalyzed carbonylation reactions in alcohol have been reported (24, 25, 26, 27), but full experimental details of the syntheses are incomplete and in most cases the yields of yS-alkoxy ester and diester products are low. A similar reaction employing stoichiometric amounts of palladium (II) has also been reported (28). In order to explore the scope of this reaction for the syntheses of yS-alkoxy esters and succinic acid derivatives, representative cyclic and acyclic olefins were carbonylated under these same conditions (Table I). The reactions were carried out in methanol at room temperature using catalytic amounts of palladium (II) chloride and stoichiometric amounts of copper (II) chloride under 2 atm of carbon monoxide. The methoxypalladation reaction of 1-pentene affords a good conversion (55% ) of olefin to methyl 3-methoxyhexanoate, the product of Markov-nikov addition. In the carbonylation of other 1-olefins, f3-methoxy methyl esters were obtained in high yields however, substitution of a methyl group on the double bond reduced the yield of ester markedly. For example, the carbonylation of 2-methyl-l-butene afforded < 10% yield of methyl 3-methyl-3-methoxypentanoate. This suggests that unsubstituted 1-olefins may be preferentially carbonylated in the presence of substituted 1-olefins or internal olefins. The reactivities of the olefins fall in the order RCH =CHo ]> ci -RCH=CHR > trans-RCH =CHR >... 

N-Methyl-N-methoxycarbamoyl chloride made by phos-genation of methoxy methyl amine hydrochloride is a very useful intermediate for the synthesis of N-methoxy ureas herbicides. However, we found the method to be unsatisfactory for the production on a large scale, because of rather low yields and also of technical difficulties. To overcome these problems, we developed a new procedure based on the reaction of phosgene with methoxy methyl amine sulfate as depicted in scheme 124. Sulfuric acid formed is easily removed by decantation (Ref. 177). 

A 3-acetoxypropyl group was used to protect an aziridine —NH group during the synthesis of mitomycins A and C acetyl, benzoyl, ethoxycarbonyl and methoxy-methyl groups were unsatisfactory. ... 

Another attempt shows the synthesis of HMF-derived vinyl polymers (Fig. 6) [38]. By the Wittig reaction, HMF and the methylated derivative 5-(methoxy-methyl)furfural (MMF) could be converted into vinyl derivatives. Radical polymerization leads to the corresponding vinyl polymers which might become substitutes for commodity polymers like polyethylene, poly vinyl chloride, and polystyrene. 

The first synthesis for methyl (Z)-2-methoxy-6-hexadecenoate was reported by Soderquist et al. [35]. The idea behind the construction of the a-methoxy functionality was the addition of a carboxy synthon to the corresponding aldehyde, in this case 5- pentadecenal, followed by methylation of the hydroxy group. This synthesis started with the Suzuki-Miyaura cross coupling of 4-bromo-l-butyl-9-borabicyclononane with (Z)-l-bromo-l-undecene, prepared as shown in Fig. (11). 

From these compounds, we selected compounds methyl, methoxy, and methoxy-methyl derivatives as R substituents, taking into consideration their molecular weight, basic efficacy, ease of synthesis, and other physical and chemical properties, and evaluated their vapor activities with their chrysanthemic derivatives in a non-heated formulation. The results presented in Figure 6 clearly demonstrate that the methoxymethyl derivate (9) shows a significantly faster action in comparison with other compounds in the non-heated formulation. As a consequence of these findings, we chose this methoxymethyl derivate to be a new synthetic pyrethroid with high vapor activity against mosquitoes [5]. 

Dihydropyridine 429 was next used for the synthesis of methyl glycoside of 5-amino-5-deoxy-DL-ido-hexopiperidonose (445). In the first step, 429 was reacted with N-bromosuccinimide to afford two bromoacetates (439 and 440). The first bromoacetate (429) was deacetylated to the bromohydrin 441. Reaction with silver oxide followed by acetylation gave a rearranged diacetate 442 (which was certainly preceded by an epoxide). The 1-0-acetyl group in 442 could be readily replaced by a methoxy group to form 443. C -hydroxylation of the... 

This phenolic amine, 5-hydroxy-2-methoxy-N-methylamphetamine is just a methyl group away from METHYL-DMA it could either be methylated to complete the synthesis, or METHYL-DMA could be demethylated to form this phenol. There is plentiful precedent for both of these reactions occuring in the body. It is always intriguing when drugs which show distinctly different actions can, in principle, intersect metabolically at a single structure. One wonders just what the pharmacology of that common intermediate might be. 

TOMSO 2-METHOXY -METHYL-5-METHYLSULFINYLAMPHETAMINE SYNTHESIS A suspension of 12.7 g... 

Method A Synthesis of Methyl (R,S)-2-Methoxy-3-Methyl-4-Pentenoate (syn-17a)... 

In 2005, Fagnou achieved the formal synthesis of (—)-allocolchicine through a palladium-catalyzed intramolecular C-H/C-X coupling [411]. The intramolecular biaryl coupling of 1,3-diarylpropane precursor 40 proceeded in the presence of Pd(OAc)2> DavePhos (41), and K2CO3 at 145 °C to furnish the seven-membered ring in 42. Deprotection of the methoxy methyl ether (MOM) group by HCl, followed by... 

Synthesis Fischer first prepared carbyne complexes (1973) by electrophilic abstraction of methoxide ion from a methoxy methyl carbene. 

Hatakeyama S, Ochi N, Numata H, Takano S (1988) A new route to substituted 3-methoxy-carbonyldihydropyrans enantioselective synthesis of (-)-methyl elenolate. J Chem Soc Chem Commun 1988 1202-1204... 

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