Tri t-butoxy

Reduction of Cholest-5-en-3-one with Lithium Aluminum Tri-t-butoxy Deuteride. 

Semmelhack et al. chose CuBr, together with either Red-Al or LiAl(OMe)3H in a 1 2 ratio, to afford presumed hydrido cuprates, albeit of unknown composition [llj. In THF, both the former Na complex and the latter Li complex are heterogeneous (and of differing reactivities), yet each is capable of 1,4-reductions of unsaturated ketones and methyl esters (Eq. 5.4). Commins has used a modified version, prepared from lithium tri-t-butoxy-aluminium hydride and CuBr (in a 3 4.4 ratio), to reduce a 3-substituted-N-acylated pyridine regioselectively at the a-site [12]. 

Selective reduction of functional groups can be achieved by chemical modification of the LiALH4 for example, lithium tri(t-butoxy)aluminium hydride [LiAIH(t-OBu)3] is a more selective reagent, and reduces aldehydes and ketones, but slowly reduces esters and epoxides. Nitriles and nitro groups are not reduced by this reagent. Carboxylic acids can be converted into the aldehyde via acid chloride with lithium tri(tert-butoxy) aluminium hydride at a low temperature (—78°C). The nitro compounds are not reduced under this condition. Thus, selective reduction of 3,5-dinitrobenzoic acid (6.45) to 3,5-dinitrobenzaldehyde (6.47) can be achieved in two steps. First, 6.45 is converted into 3,5-dinitrobenzoyl chloride (6.46) and then LiAlH(t-OBu)3 reduction of 6.46 gives 6.47. 

Lithium Tri(t-Butoxy)aluminium Hydride Li+ (tBuO)sAlH... 

Our synthesis of the proposed structure for blattellastanoside A is summarized in Figure 7.11.12 The ketone E of Figure 7.9 was reduced with lithium tri(t-butoxy)aluminum hydride to give A, whose acetate B... 

The complex was used for the synthesis of 22-dihydroergosterol, a fungal steroid, and for the synthesis of the previously unknown epiergosterol (oxidation to the 3-ketone followed by reduction with lithium tri-t-butoxy aluminum hydride ). 

When treated with excess LAH, acid chlorides are reduced to give alcohols because two equivalents of hydride attack. Selective hydride-reducing agents, such as lithium tri(t-butoxy) aluminum hydride, can be used to prepare the aldehyde. 

Lithium aluminium tri-t-butoxy hydride rapidly reduces imidoyl chlorides to imines under very mild conditions/ an improvement over previous methodology. 

BMD bismethylenedioxy group LA(tBuO)3H lithium tri-t-butoxy aluminum... 

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