Metal carbenoid mediated ring opening of furan-2-yloxy derivatives. Stereoselective synthesis of 2,4-hexadienedioic acid and 6-aryl-1-oxo-2,4-hexadienoic acid derivatives

2-Methoxy- and 2-trimethylsilyloxyfuran undergo facile ring opening reactio n upon treatment with metal carbenoid. Treatment of 2-methoxyfuran with eth yl diazoacetate and aryl-alpha -diazocarbonyl compounds under metal catalys is afforded (2Z,4E)-hexadienedioate and 6-aryl-6-oxo-(2Z,4E)-hexadienoates respectively. When 2-trimethylsilyloxyfuran was used, desilylation occurred to give directly the monoprotected (Z,E)-muconic acid and 6-aryl-6-oxo-(2Z ,4E)-hexadienoic acids. (C) 2001 Elsevier Science Ltd. All rights reserved.