ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A new versatile and efficient regio-, diastereo-, and enantioselective synthesis of vicinal diols s-trans-4, s-trans-5, and s-cis-4 is described. Symmetrical ketones are converted into their SAMP-or RAMP-hydrazones which are then silylated with (isopropyloxy)dimethylsilyl chloride, followed by ozonolysis to afford the α-silyl ketones (R)-2 of high enantiomeric purity (ee 90- ≥ 98%). On the other hand, methyl ketones, after conversion into the corresponding (-)-(S)-1-amino-2-(methoxymethyl) pyrrolidine (SAMP) hydrazones, are silylated and then alkylated with RI to afford unsymmetrical α-silyl ketones (S)-3 of high enantiomeric purity (ee 90- ≥ 98%). The reduction of the above obtained α-silyl ketones with L-Selectride, followed by oxidative cleavage of the C—Si bond gives rise to s-trans-4, s-trans-5, and s-cis-4 with high diastereoselectivity (de 95- ≥ 98%) and without racemization (ee ≥ 90- ≥ 98%).
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19900730704
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