Dichloromethyl methyl ether, reaction with

Titanium tetrachloride induces reaction with dichloromethyl methyl ether to give a, (3-unsaturated aldehydes.127... 

Few data are available on the electrophilic substitution of dibenzofurans containing more than one substituent. 1,4-Dimethyldibenzofuran affords, as expected, the 2-aldehyde on reaction with dichloromethyl methyl ether and tin(IV) chloride. " The nitration of 2,4-dimethyldibenzofuran has also been studied. Acetylation of 4-methoxy-7-nitro- and 8-nitrodibenzofuran occurs exclusively at the 1-position. Similarly, both 4,6- and 3,4-dimethoxydi-benzofuran undergo bromination and acetylation at the 1-position. The acetylation of 1,3-dimethyl-, 1,4-dimethyl-, and 2,4-dimethyl-7-methoxydibenzofuran have been studied the acetyl group enters the 8-position. The chlorination of 3,7-dichlorodibenzofuran has also been studied. ... 

Dimethylsulfoxonium methylide. 14,152 15,147 16,146 17,126-127 18,148 19,139 Polyhomologation. The ylide provides the methylene unit in chain extension of triorganoboranes. Besides oxidative workup to generate alkanols, the replacement of the boron atom by a hydroxylated carbon on reaction with dichloromethyl methyl ether gives compounds with trident carbon chains. 

Alkylborinic esters, obtained from alkylboronic esters and an organometallic reagent, are converted into the corresponding ketones by the reaction with dichloromethyl methyl ether in the presence of a hindered base, followed by oxidation with hydrogen peroxide in pH 8 buffer or with anhydrous trimethylamine Ar-oxide18. 

FormyMestannylation. A trimethylstannyl group attached to an aromatic ring or an alkenyl position is liable to replacement on reaction with dichloromethyl methyl ether. Aldehydes are formed. 

Titanium tetrachloride induces reaction with dichloromethyl methyl ether. 

Frontier orbital theory predicts that electrophilic substitution of pyrroles with soft electrophiles will be frontier controlled and occur at the 2-position, whereas electrophilic substitution with hard electrophiles will be charge controlled and occur at the 3-position. These predictions may be illustrated by the substitution behaviour of 1-benzenesulfonylpyr-role. Nitration and Friedel-Crafts acylation of this substrate occurs at the 3-position, whereas the softer electrophiles generated in the Mannich reaction (R2N=CH2), in formylation under Vilsmeier conditions (R2N=CHC1) or in formylation with dichloromethyl methyl ether and aluminum chloride (MeO=CHCl) effect substitution mainly in the 2-position (81TL4899, 81TL4901). Formylation of 2-methoxycarbonyl-l-methylpyrrole with... 

The base-induced reaction of dichloromethyl methyl ether with trialkyl- and triarylboranes also provides a powerful method for the preparation of the corresponding tertiary carbinols.1617 fn this case, all three groups transfer readily from horon to carbon under mild conditions, and oxidation with alkaline hydrogen peroxide provides the tertiary alcohol ... 

Allyl- and benzyl-thiophenes may be cyclized by a direct Bradsher reaction, using dichloromethyl methyl ether or related dichloroalkyl methyl ethers and tin(IV) chloride catalysis to give the corresponding benzo- or dibenzo-thiophenes in 55-60% yield (73JCS(P1)1099). Thus substituted thiophenes having a benzyl group at either the 2- or 3-position, e.g. (349), when treated with a 1,1-dichloroalkyl methyl ether and tin(IV)... 

Nakajima has shown that a-cyclopropyl acyl silane (23) results from reaction of 1-trimethylsilyl cyclopropyl lithium with dichloromethyl methyl ether at low temperature in THF solution, in a reaction said to involve a carbene intermediate and a 1,2-silicon shift (Scheme 56)147. 

Another 1,2-silyl migration from C to C was found during the reaction of an a-silyl cyclopropyllithium 42 with dichloromethyl methyl ether 43 to give the silyl ketone 44 (equation 36)87. 

The preparation of 2-methoxy-l,3-dithiolane (292) is based on the reaction of dichloromethyl methyl ether with the disodium salt of ethanedithiol in acetonitrile (72HCA75). 

Nitration and FriedelCrafts acylation of 1-phenylsulfonylpyrrole occur at the 3-position, whereas the softer electrophiles generated in the Mannich reaction (R2N+=CH2), in formylation under Vilsmeier conditions (R2N+=CHC1) or in formylation with dichloromethyl methyl ether and aluminum chloride (MeO+=CHCl), effect substitution mainly in the 2-position. 

Formylation of unsaturated silanes. a, -Unsaturated aldehydes can be prepared by reaction of vinylsilanes with dichloromethyl methyl ether in the presence of 1 equiv. of TiCl, (equation 1). The enals have the (E)-conflguration, regardless of... 

Summary Methoxy-bis[tris(trimethylsilyl)silyl]methane (4), the first geminal di(hyper-silyl) compound with a central carbon atom, was prepared by the reaction of tris(tri-methylsilyl)silyl lithium with dichloromethyl methyl ether. The structure of 4, which is characterized by considerable distortions due to the spatial demand of the two (MesS aSi groups, is discussed on the basis of an X-ray crystal structure analysis. 

Methoxy-bis[tris(trimethylsilyl)silyl]methane (4) - the first compound bearing two hypersilyl groups at a carbon atom - was synthesized by the reaction of tris(trimethylsilyl)silyllithium (1) with dichloromethyl methyl ether in a yield of 35 % In view of the extreme bulkiness of the two hypersilyl substituents, the ease of the formation of 4 is really surprising. But the reaction pathway is easily understood as a consecutive replacement of the two chlorine atoms of the dichloromethyl methyl ether by the silanide 1 (Eq. 1). 

Table 3 Acid Chlorides from the Reaction of Dichloromethyl Methyl Ether° with Carboxylic Acids...

Aldehyde synthesis [before references]. A fairly general route to aromatic aldehydes is illustrated by the synthesis of mesitylaldehyde by TiCl4-catalyzed reaction of mesitylene with dichloromethyl methyl ether (which see, this volume). 

Carbonylation An enone that bears chirality at both a and 3 carbon atoms can be synthesized through successive reactions of a chiral borane with an alkene and an alkyne, followed by exposure to acetaldehyde. Further treatment of the resulting alkenylborane with dichloromethyl methyl ether and EtjCOLi, and finally with HjO affords the product. 

E)-a, -Unsaturated aldehydes. The reaction of dichloromethyl methyl ether with vinylsilanes catalyzed by TiCU leads to K,/8-unsaturated aldehydes (equation T).7... 

A recent issue of the Journal of Medicinal Chemistry has just presented an article describing the reaction of 6-methoxytetrahydrobenzopyran with dichloromethyl methyl ether, and approximately equal amounts of all three of the possible isomers were obtained. That would have been the first step towards making the prototypic compound 7-(2-aminopropyl) 6-methoxy-1,2,3,4-tetrahydrobenzopyran. Just as the benzofurans were all named as F-compounds, this, as a benzopyran, would have been a P compound, but P also is used for proscaline, and there would have been some repair-work needed for these codes. 

Following the outlined concept we succeeded in synthesizing methoxy-bis[tris(trimethylsilyl)silyl]-methane (2) by the reaction of 1 with dichloromethyl methyl ether (molar ratio 2 1) [1]. The reaction of 1 with ter -butyl formate (2 1) afforded di(hypersilyl)methanol (3). Despite the extreme steric shielding, the alcohol 3 is reactive and was converted with acetyl chloride into the acetate 4 and underwent transesterification with methyl formate to give 5 [2]. Recently we obtained... 

Hine, J., Rosscup, R. J., and Duffey, D.C. (1960) Formation of the intermediate methoxychloromethylene in the reaction of dichloromethyl methyl ether with base. Journal of the American Chemical Society, 82,6120-6123. 

A novel and more profitable route to Omethyl thioformate depends on the reaction of dichloromethyl methyl ether with potassium Oethyl dithiocarbonate the product (370) decomposed thermally at 200—220 C to... 

Dichloromethyl methyl ether has been prepared by the chlorination of chlorodimethyl ether in the liquid5-4 or gas phase,5 by the reaction of chlorodimethyl ether with sulfuryl chloride and benzoyl peroxide,6 7 and by the treatment of methyl formate with phosphorus pentachloride.8-10... 

Phosphorus pentachlonde, for conver sion of d l 10 camphorsulfomc acid to acid chloride, 46,14 reaction with methyl formate to yield dichloromethyl methyl ether, 47, 47... 

Several chlorophyll derivatives have been prepared by electrophilic substitution, inter alia by formylation reactions. Adopting methods from corrin chemistry.50 alkylation with chloro-methyl methyl ether (caution toxic),32k chloromethyl methyl sulfide,51 and dichloromethyl methyl ether (caution toxic)52 in the presence of Lewis acids are the methods of choice to introduce carbon residues into the chlorin frame work. The compounds listed below have been prepared by these methods. 

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