Lithium, tris

That means that this method is a neat little way one can get the ever lovely MDEA (Methylenedioxyethyl amphetamine, the softer cousin of X). Strike hears you asking So if one uses lithium tri-methylborohydride can one get methamphetamine out of that nitro group . Good question. Unfortunately the answer is no. The authors say Interestingly, N-alkylated products were not produced when other alkylborohydrides were used." Fair enough. Here s the recipe ... 

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. 

A cold (0°) solution of 15 g (0.039 mole) of cholest-4-en-3-one, mp 79-80°, in 200 ml of ether-benzene (8 1) is added dropwise to 0.05 mole of lithium tri-t-butoxyaluminum hydride in ether-diglyme at —40° to —50°. The mixture is allowed to stand overnight at 0° and then hydrolyzed by treatment with ice, 5 N sodium hydroxide and Rochelle salt. Evaporation of the washed and dried ether extracts and crystallization of the residue from ethyl acetate affords 13 g (87 % yield) of nearly pure cholest-4-en-3j9-ol, mp 126-129°. One recrystallization from the same solvent gives the pure product as large needles mp 131-132°, [a]o 46° reported mp 132° [a]c, 44° (benzene). 

A much more stereoselective and milder reducing agent is lithium tri-r-... 

Reductions with lithium tri-/-butoxyalu-minum hydride, 99... 

The introduction of the l/, 2j5-methylene function into cortical hormones is best carried out by starting with the A -3)S-aIcohols (7) which are prepared by lithium aluminum hydride or lithium tri-t-butoxyaluminum hydride reduction of the corresponding A -3-ketones. 

The procedure described is a modification of the general procedure of Angyal2 for the preparation of aldehydes from benzylamines by the Sommelet reaction. Isophthalaldehyde has been prepared from w-xylene by preparation of the tetrachloro derivative and hydrolysis,3 from isophthaloyl chloride by the Rosenmund reaction,4 from a,a -dibromo-m-xylene by the Sommelet reaction,5 and from isophthaloyl chloride by reduction with lithium tri-Cbutoxyaluminumhydride.6... 

The reduction of the /er/-butyldimethylsilyl protected imide 10b with lithium tri-xeobutylboro-hydride in diethyl ether at —109 °C proceeds with opposite selectivity to provide a >99 1 mixture of lib and 12b in 98% yield44. 

Enantiomerically pure 3-tolyl-2-sulfinyl-2-cyclopentenone 37 undergoes smooth, mild and diastereoselective conjugate hydride addition with lithium tri(sec-butyl)borohydride to afford ultimately 3-tolylcyclopentanone 38 in 93% enantiomeric purity (equation 35)78. The absolute stereochemistry of product 38 is consistent with a chelated intermediate directing hydride addition from that diastereoface containing the sulfoxide lone pair. 

Die Kalium-trialkyl-hydrido-boratezersetzen sich an der Luft und werden daher ohne Isolierung eingesetzt. Kalium-triathyl-hydrido-borat ist z.B. aus Kaliumhydrid und Triathyl-boran erhaltlich1 und hat ein ahnliches Reduktionsvermogen wie Lithium-tri-athyl-hydrido-borat (s.S. 14). 

Lithium-tri-tert.-butyloxy-hydrido-aluminat5 6 Zu einer Losung von 38 g (1 Mol) Lithiumalanat in 2,5 / abs. Diathylather werden unter Riihren und unter Stickstoff Iangsam 231 g (3,15 Mol) tert.-Butanol in 1 / abs. Diathylather getropft. Unter Wasserstoff-Entwicklung scheidet sich gegen Ende der Reaktion ein voluminoser Niederschlag ab. Man dekantiert, wascht mit Diathylather und trocknet Ausbeute 254 g (100% d.Th.). 

Lithium-tri-tert.-butyloxy-hydrido-aluminat ist ein auBerst selektives Reduktions-mittel8. Es reduziert... 

Die Cyan-Gruppe wird durch Alkalimetallboranate bei 20° meist nicht angegrif-fen3-5. Mit Lithium-tri-tert.-butyloxy-hydrido-aluminat4 und Lithiumalanat5 kann die Oxo-Gruppe selektiv neben der Cyan-Gruppe reduziert werden. 

Natrium-trimethoxy-hydrido-borat Lithium-tri-tert. -bu tyloxy-hydrido-aluminat Lithium-(tetrakis-[N-dihydropyridyl]-aluminat)... 

Auch Lithium-tri-tert.-butyloxy-hydrido-aluminat reduziert cyclische Carbonsaure-anhydride zu den Lactonen1 bzw. Hydroxy-lactonen (Lactanolen) (s. S. 229)2 z.B. ... 

---