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Preparation of Chiral Hydroxy Carbonyl Compounds and Diols by Ozonolysis of Olefinic Isoborneol and Fenchol Derivatives: Characterization of Stable Ozonides by 1 H‐, 13 C‐, and 17 O‐NMR and Electrospray Ionization Mass Spectrometry
Author(s) -
Kostova Kalina,
Dimitrov Vladimir,
Simova Svetlana,
Hesse Manfred
Publication year - 1999
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/(sici)1522-2675(19990908)82:9<1385::aid-hlca1385>3.0.co;2-y
Subject(s) - chemistry , ozonolysis , allylic rearrangement , electrospray ionization , carbon 13 nmr , mass spectrometry , nmr spectra database , mass spectrum , organic chemistry , catalysis , spectral line , chromatography , physics , astronomy
The allylic and homoallylic alcohols 1 – 8 , prepared from (+)‐camphor and (−)‐fenchone, were ozonized in Et 2 O at −78° and treated with Et 3 N or LiAlH 4 to give the chiral hydroxy carbonyl compounds 9 – 16 and the diols 17 – 24 , respectively ( Scheme 1 ). In the case of the diols 19 and 24 , the formation of new chiral centers proceeded with high diastereoselectivity. These diols were prepared highly diastereoselectively also by LiAlH 4 reduction of the hydroxy carbonyl compounds 11 and 16a , respectively ( Scheme 2 ). The absolute configuration of the new chiral centers in 19 and 24 was determined by X‐ray and NMR methods. The ozonization of compounds 2 , 3 , 7 , and 8 provided the relatively stable hydroxy‐substituted 1,2,4‐trioxolane derivatives (ozonides) 37 – 40 ( Scheme 5 ) which were characterized by 1 H‐ and 13 C‐NMR spectra, ESI‐MS, and natural‐abundance 17 O‐NMR spectra.