Sodium bis 2-methoxyethoxy aluminium

Sn2 addition 413 Sn2 displacement 215 Sn2 lactone opening 412 ff. sodium bis(2-methoxyethoxy)-aluminium hydride see Red-Al sodium chlorite 516 - oxidation 772 sodium hypochlorite 550 f. sodium naphthalenide 739 f. sodium trimethoxyborohydride 390 SOMO 409... 

On treatment with sodium bis (2-methoxyethoxy)aluminium hydride (Scheme 16), 122 gave the aldehyde 123, which was converted by standard synthetic operations, into the methyl-O-benzylester 124. Acid hydrolysis of 124 followed by allylic epoxidation of the diol furnished the p-oxirane 125. On heating 125 in water containing sodium benzoate a remarkable chain of chemical events took place that resulted in the generation of (+)-pancratistatin (94) in 2% overall yield starting from bromobenzene. 

An elegant stereospecific synthesis of (+)-muscarine (2 R = NMe3) has been achieved by reduction of the epoxide (1) (easily produced from D-mannitol) with sodium bis-(2-methoxyethoxy)aluminium hydride to give predominantly (2 R = OH) on monotosylation, this forms (2 R = OTs). Chromatographic resolution and treatment with trimethylamine yielded (-l-)-muscarine (2 R = NMea).1... 

Berberines are reported to be reduced to dihydroberberines rather than the tetrahydro-compounds by sodium bis(2-methoxyethoxy)aluminium hydride.80 Partial reduction of coralynium salts affords the tertiary dienamine (55), autoxida-tion of which, at pH 8, yields the betaine (56) this can be oxidized by peracids to 6 -acetylpapaveraldine (57), obtainable directly from the dienamine (55) by photolysis in the presence of air. The diketone reacts with hydrazine to give the 1,2-diazine (58).81... 

Completely stereospecific frans-reduction of acetylenic alcohols to -allyl alcohol is reported with sodium bis(2-methoxyethoxy)aluminium dihydride (SMEAH or Red-Al), where LiAlH4 in various solvents is less selective. 

However, with less reactive hydrides such as LiAlH(OEt)3 and DIBAL, the iminoalanate A and B are not formed (Scheme 6.34). The intermediate iminium salt can be hydrolyzed to RCHO. Red-Al [sodium bis(2-methoxyethoxy)aluminium hydride] can also be used to get even better yield of aldehyde. 

Red-Al = Sodium bis(2-methoxyethoxy)aluminium hydride The iminoalane A obtained by the reaction of nitrile with DIBAL (diisobutylaluminium hydride) on hydrolysis gives the aldehyde via imine B (Scheme 6.35). 

Red-Al [sodium bis(2-methoxyethoxy)aluminium hydride] reduces aliphatic halides and aromatic halides to hydrocarbons. Reductive dehalogenation of alkyl halides is most commonly carried out with super hydride. Epoxide ring can also be opened by super hydride. 

RDB Sodium dihydrobis(2-methoxyethoxy)aluminate (sodium bis(2-methoxyethoxy)aluminium... 

Na[AlH2(OCH2CH20CH3)2l (RED-AL) (sodium bis-[2-methoxyethoxy]-aluminium hydride) Ethers, toluene -78 to RT ester — alcohol ketone — alcohol aldehyde — alcohol alkyl halide — alkane epoxide — alcohol Dt,U-unsaturated enone —> allvlic alcohol... 

Furthermore, reduction of stearoylvelutinal (7.14) with Red-Al (sodium bis 2-methoxyethoxy)aluminium hydride) in toluene-THF gave directly lactaropallidine in a single step (29). A possible mechanism for this epoxyde-ketone rearrangement is reported in Scheme 4. 

Stereospecific reduction of acetylenic alcohols to E- allylic alcohols by means of sodium bis(2-methoxyethoxy)aluminium hydride (SMEAH) (see 1st edition). 

Additional data on the thermal rearrangement of cnrfo-cineole halohydrins and dihalides to halopinol derivatives (Vol. 8, p. 44) have been reported. ° In further attempts to synthesize 2,3-didehydro-l,8-cineole, nitrosation of the endo- and exo-aminocineoles (157) results in a stereospecificity not observed with dehydration of the corresponding alcohols (Vol. 8, p. 41) endo- 51) yields (158) and exo- 51) yields (159). The successful route to 2,3-didehydro-1,8-cineole involves reduction of 2-hydroxyimino-l,8-cineole with sodium bis-(2-methoxyethoxy)aluminium hydride to the corresponding aziridine followed by nitrosation interestingly, LiAlH4 reduction of 2-hydroxyimino-l,8-cineole is the most efficient route for the synthesis of (160). Bamford-Stevens reaction. 

Sodium bis-(2-methoxyethoxy)aluminium hydride (ref. 84) and lithium tri-tert-butoxyaluminium hydride (ref. 85) showed excellent stereoselectivity for podophyllotoxin compared with other reagents. However, these reagents have the disadvantage that low temperature (-75 C) is required to obtain satisfactory yield. Although the stereoselectivity was inferior to that of the above-mentioned aluminium hydride complexes, borane-terf-butylamine complex (ref. 86) and borane ammonia complex (ref. 87) gave the products in more than 90% yield. The reactions proceeded at room temperature, and borane-tert-butylamine complex did not require the use of a nitrogen stream. 

By reaction of the Cg-hydroxyketone (3R)-58 with isopropenyl methyl ether, the acetonide 59 was obtained. Subsequent reaction with but-3-yn-2-ol (60), acetylation and dehydration gave the diacetate 61 which was reduced with sodium bis-(2-methoxyethoxy)aluminium hydride (SMEAH) to (3/ )-3-hydroxy-p-ionol (62) Scheme 15). 

From Secondary Phosphine Oxides and Sulphides.—A novel reaction of phosphinates with sodium bis-(2-methoxyethoxy)aluminium hydride has been used to synthesize phosphine oxides, The complex hydride is believed to generate a secondary phosphine oxide anion from the phosphinate, and this ion may be trapped by an alkyl halide to give a phosphine oxide. The reaction is general for tetrahedral esters, and is... 

Reagents i, OH ii, HOAc-HjO iii, air iv, LiBH4 v, HO Ac vi, dil. acid vii, sodium bis-(2-methoxyethoxy)aluminium hydride viii, trimethyl orthoformate-methanol. 

The first total synthesis of Cet /ojc is that of Masanao Matsui. [228] The starting material is )8-ionone [229] its side-chain double bond can be hydrogenated regioselectively on a copper catalyst. The side-chain is then extended by three carbon atoms by means of a Darzens reaction [230], followed by a Knoevenagel condensation. The (JS/Z)-isomeric mixture (1 1) of acids is separated by fractional distillation of their ethyl esters the ( )-isomer is hydrolysed and cyclised with trifluoroacetic add to sclareolide. Reduction of the latter with Vitride (sodium bis(2-methoxyethoxy)aluminium hydride) and ether formation then produces Cetalo . ... 

---