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Preparation of donor‐acceptor‐substituted vinylcyclobutanes
Author(s) -
Gruseck Ursula,
Heuschmann Manfred
Publication year - 1990
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19901230924
Subject(s) - chemistry , wittig reaction , dioxolane , cycloaddition , acceptor , reagent , medicinal chemistry , stereochemistry , nmr spectra database , organic chemistry , spectral line , catalysis , physics , condensed matter physics , astronomy
2‐Methylen‐1,3‐dioxolane ( 1 ) and the methyl acrylates or crotonates 2 form [2+2] cycloadducts 3 which are reduced to give alcohols 6 . Oxidation of these alcohols at low temperatures leads to unstable aldehydes 7 , which either rearrange to dihydropyrans 5 or react with Wittig(‐Horner) reagents to afford donor‐acceptor‐substituted vinylcyclobutanes 8 . The cis ‐vinylcyclobutane 8g is prepared by [2+2] cycloaddition of dioxolane 1 and methyl (2 E ,4 Z )‐hexadienoate ( 9 ). The configurations and preferred conformations of the vinylcyclobutanes 8 have unequivocally been assigned on the basis of 13 C‐and 1 H‐NMR spectra.