Lithium aluminum tritide

Labeling with tritium in position 15 could easily be accomplished by reduction of retinaldehyde with sodium borotritide (Mayer and Isler, 1971) or of retinoic acid esters with lithium aluminum tritide, and, again, oxidation of the tritiated retinol (Kaegi et aL, 1982c) to retinaldehyde-15- H. Because of the favorable isotope effect, most of the isotope should stay attached to the aldehyde group. However, Futterman et aL (1979) found that all-frany-retinaldehyde-15- H is inadequate as a tracer for 11-c/y-retinaldehyde formation in a biological system. 

To adapt the reactions to the use of tritium, the following observations must be kept in mind. The preparation along these lines would be feasible for obtaining tritiated compounds of very low specific activity. Lithium aluminum tritide, being unstable, is available only at relatively low specific activities. Quenching a reaction with tritiated water, usually done in large excess, would be feasible only... 

The known 25-hydroxycholesterol acetate was brominated and the resulting 25-bromocholesterol was reduced with lithium aluminum tritide to give cholesterol-25- H (Joly et al., 1969). 

Preparation of Compounds Labeled with Tritium and Carbon-14 4.3.11 Lithium Aluminum Tritide (LiAl H4)... 

Figure 4.74 Applications of high specific activity lithium aluminum tritide ( )...

---