Organoaluminum reagents alcohol synthesis

Yamamoto and Maruoka investigated the reaction of chiral acetals with organoaluminum reagents. Unprecedented regio- and stereochemical control was observed in the addition of trialkylaluminums to chiral a,/3-unsaturated acetals derived from optically pure tartaric acid diamide [83]. The course of the reaction seemed to be highly influenced by the nature of substrates, solvents, and temperature. These findings provide easy access to optically active a-substituted aldehydes (84), /3-substituted aldehydes (85), a-substituted carboxylic acids (86), or allylic alcohols (87). Because optically pure RJi)- and (5,5)-tartaric acid diamides are both readily available, this method enables the predictable synthesis of both enantiomers of substituted aldehydes, carboxylic acids, and allylic alcohols from a,/3-unsaturated aldehydes (Sch. 54). 

Organoaluminum reagents are important in Ziegler-Natta catalysts (Section 11.5), but are not widely used in organic synthesis. They can be violently pyrophoric and water-sensitive and can add readily to alkenes. The Aufbau reaction (Eq. 14.15) is a commercial synthesis of C12-C16 linear alcohols that are useful in detergents. 

Addition of Grignard reagents to ketones to form alcohols is a class of the most fundamental reactions in organic synthesis. Much data on selectivities of this reaction are available. Yamamoto et al. utilized a highly bulky organoaluminum compounds as a... 

Ring cleavage. Diastereoselective cleavage of C2-symmetrical 1,3-dioxanes has been effected by reagents prepared from organoaluminums. For example, reduction with a species obtained from Me Al and C6F5OH is useful for synthesis of chiral secondary alcohols. ... 

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