Oxotungsten tetrachloride catalyzes the conversion of β-hydroxy carboxylic acids to olefins, in the presence of base. The reaction proceeds in high yield, stereospecifically, and with high catalyst turnover. Examination of the likely stoichiometric steps for β-hydroxy carboxylic acid activation shows the formation of intermediate chelates, structures of which were studied by1H NMR. The role of the base was probed by using both1H and183W NMR, and it was shown that base simply deprotonates the chelate; base does not coordinate to the W center. β-Lactones were the initial products of this sequence from which decarboxylation occurred to give the olefinic product.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry