176650-28-5Relevant articles and documents
A practical route to regiospecifically substituted (R)- and (S)-oxazolylphenols
Scheurer, Andreas,Mosset, Paul,Bauer, Walter,Saalfrank, Rolf W.
, p. 3067 - 3074 (2007/10/03)
New, diversely substituted phenolic oxazolines 14a-d and 15a-d were prepared by two complementary routes A and B, starting from salicylic derivatives 4-7 and various enantiomerically pure 1,2-amino alcohols 13a-d. In route A, the 1,2amino alcohols 13a-d were directly condensed with the salicylic acids 5 and 7, using the Appel reaction, whereas in route B the amino alcohols 13b-d were treated with the 2-hydroxybenzonitriles 4 and 6, under Witte-Seeliger conditions. The latter route was advantageous for L-valinol 13b and L-tert-leucinol 13c, while route A was the method of choice for the new, sterically demanding amino alcohol 13a, prepared from D- and L-serine. The nitro group in the salicylic derivatives 5 and 6 was introduced by means of a regiospecific ipso substitution of a tert-butyl group by nitric acid. The structure of the nitro product 5 was unambiguously assigned by NOE spectroscopy on the basis of the recently developed DPFGSE-ROE pulse sequence.
