Triethylsilane keto acids

Treatment of A 8(9)-dehydroestradiol with trifhioroacetic acid and triethylsilane gives estradiol in 96% yield (Eq. 86).239 The 3-methyl ether is similarly reduced to the 3-methyl ether of estradiol in >50% yield.239 The structurally related 18-ethyl and 18-propyl 17-keto compounds experience reduction of the A8(9) function in excess of 70% yield without concomitant reduction of the 17-keto... 

Reduction of the keto group in naphtho derivative 115 with sodium borohydride results in 69% of the alcohol 116 (Scheme 23, Section 2.1.3.3 (1999PHA645)). Further triethylsilane reduction gives 117 in 67% yield. Synthesis of a series of pyrrolo-benzazepine and pyrrolo-benzothiazepine acetic acids (Scheme 77, Section 5.1.1 (1994MI385)) includes reduction of ketoesters 380 into corresponding hydroxyl esters, subsequent deoxygenation with iodine/PPhs and hydrolysis. 

Reduction of an aralkyl keto group. A recent example of this transformation is the conversion of 1 into 2 in 957o yield (pure) with 2.5 equiv. of triethylsilane and trifluoroacetic acid. ... 

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