87791-16-0Relevant academic research and scientific papers
Synthesis of 2-Acyloxy- and 2-Alkoxy-3-oxoglycals and of Their Dibromo Adducts
Kunz, Horst,Weissmueller, Joachim
, p. 1561 - 1575 (2007/10/02)
The 2-hydroxy-3-oxoglycal derivatives 5a, 5b, and 11 - acetyl-, pivaloyl-, and methyl-protected, respectively, at their hydroxylic functions - are synthesized by oxidation with dimethyl sulfoxide/acetic anhydride or chlorosulfonyl isocyanate of the corresponding 1-O-acylglucopyranoses 3a, 3b, and 9, respectively, each containing a free 3-hydroxy group.Only in the case of the acetyl derivative 3a the oxidation is immediately followed by the elimination of the 1-acetyloxy substituent.In contrast, the oxidation of both the pivaloyl derivative 3b and the methyl derivative9 yields mainly the corresponding 3-ulose 4 and 10, respectively.Here, the elimination of the 1-acyloxy group must be completed by diazabicycloundecene (DBU). - Bromine is added stereoselectively to the hex-1-enopyran-3-uloses 5a, 5b, and 11 forming the D-ribo-configurated 1,2-dibromides 13/14.Moreover, in the cases of the pivaloyl and the methyl derivates only theα anomers 13 are formed.The configurations of the adducts have been estimated by means of NMR and CD spectra.
