Alcohols by reduction

The preparation of thiazole alcohols by reduction is also discussed in Chapter VIII. 

PREPARATION OF ALCOHOLS BY REDUCTION OF CARBOXYLIC ACIDS AND ESTERS... 

Preparation of Alcohols by Reduction of Carbonyl Functional Groups... 

Table 17 2 summarizes the reactions of aldehydes and ketones that you ve seen m ear her chapters All are valuable tools to the synthetic chemist Carbonyl groups provide access to hydrocarbons by Clemmensen or Wolff-Kishner reduction (Section 12 8) to alcohols by reduction (Section 15 2) or by reaction with Grignard or organolithmm reagents (Sections 14 6 and 14 7)... 

The 36d-LAH complex has been used in the asymmetric synthesis of (3-allenic alcohols by reduction of enynols (41) as shown in eq. [14]. Although similar... 

A typical probe reaction for estimating catalytic properties in selective hydrogenations is the hydrogenation of cinnamaldehyde. This molecule contains both a C=C and a C=0 double bond, thus the formation of hydrocinnamaldehyde and/or cinnamyl alcohol by reduction of the one or the other, or the formation of phenyl propanol in the case of complete reduction may indicate the potential of the catalyst for other fine chemical transformations. Indeed, this reaction was one of the first to be tested by CNT-supported catalysts [120]. Noble metals show a high activity in this reaction and... 

Nakamura, K., Takenaka, K., Fujii, M. and Ida, Y., Asymmetric synthesis of both enantiomers of secondary alcohols by reduction with a single microbe. Tetrahedron Lett., 2002,43, 3629-3631. 

Bouvealt-Blanc method org chem) A laboratory method for preparing alcohols by reduction of esters utilizing sodium dissolved in alcohol. bti,vo blan, meth-3d j bp See boiling point. 

Acrolein (CHj=CHCHO, also known as 2-propenal) is a a,P-unsaturated aldehyde that can be transformed reducfively to saturated or unsaturated alcohols by reduction of the C = 0 or C = C double bonds (Claus 1998). In addition, a,P-unsaturated aldehydes may undergo hydration reactions in aqueous solutions. It was observed that, under acidic (pH12) conditions, acrolein is hydrated to 3-hydroxypropanal (Jensen and Hashtroudi 1976). In a natural subsurface environment, where pH may range from 6.5 to 8.5, the hydration rate of acrolein increases with the pH and its half-life decreases. Based on an experiment to analyze effects of iron on acrolein transformation, Oh et al. (2006) note that, under acidic conditions (e.g., pH = 4.4), acrolein disappears rapidly from solution in the presence of elemental iron (Fig. 16.1). Moreover, the formation of... 

Complex hydrides can be used for the selective reduction of the carbonyl group although some of them, especially lithium aluminum hydride, may reduce the a, -conjugated double bond as well. Crotonaldehyde was converted to crotyl alcohol by reduction with lithium aluminum hydride [55], magnesium aluminum hydride [577], lithium borohydride [750], sodium boro-hydride [751], sodium trimethoxyborohydride [99], diphenylstarmane [114] and 9-borabicyclo[3,3,l]nonane [764]. A dependable way to convert a, -un-saturated aldehydes to unsaturated alcohols is the Meerwein-Ponndorf reduction [765]. 

As a consequence of the wide choice of hydride reagents the classical methods such as reduction with sodium in ethanol almost fell into oblivion [579, 520]. Nevertheless some old reductions were resuscitated. Sodium di-thionite was found to be an effective reducing agent [262], and the reduction by alcohols [309] was modified to cut down on the temperature [755] or the time required [527], or to furnish chiral alcohols ( in good yields and excellent optical purity ) by using optically active pentyl alcohol and its aluminum salt [522]. Formation of chiral alcohols by reduction of pro-chiral ketones is... 

Preparation of a Na-Protected a-Amino Aldehyde via Oxidation of the Corresponding 11-Amino Alcohol Preparation of a (1-Amino Alcohol by Reduction of the Mixed Anhydride of a Na-Protected a-Amino Acid 35 ... 

Preparation of a (1-Amino Alcohol by Reduction of a N"-Protected a-Amino Acid General Proce-... 

Table 3.35. Linkers for the preparation of alcohols by reductive cleavage.

Table 7.1. Preparation of alcohols by reduction of carbonyl compounds.

In some circumstances, the production of a 2-halo alcohol by reduction of the carbonyl group of an a-halo ketone with metal hydrides is a useful synthetic reaction ... 

Convert the ester functions to primary alcohols by reduction. 

In Section 10-6B, we learned to remove the hydroxyl proton from an alcohol by reduction with an active metal such as sodium or potassium. This reaction generates a sodium or potassium salt of an alkoxide ion and hydrogen gas. 

For the synthesis of (7 )-alcohols by reduction of the corresponding ketones, an E. coli whole-cell catalyst was constructed based on an ADH from L. kefir. Some preparative examples using these designer cells are summarized in section 9.4. 

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