REACTIONS OF 2,5-DIHYDRO-2,5-DIMETHOXY-FURAN WITH PHENYLSELENENYLCHLORIDE - REGIOCONTROLLED AND STEREOCONTROLLED GENERATION OF HIGHLY FUNCTIONALIZED C-4 BUILDING-BLOCKS

An efficient protocol for stereo-and regiocontrolled synthesis of smal l polyfunctional molecules is presented. The stereospecific addition o f PhSeCl to 2,5-dihydro-2,5-dimethoxy-furan 1 in solvents, such as met hylene chloride and methanol, gives cyclic and linear acetals 2 and 3, depending on the solvent used. Emphasis is given to the regiocontroll ed hydrolysis of acetal groups for the preparation of stereodefined an d highly functionalized C-4 synthons, such as 8, 9 and 13. (C) 1997 El sevier Science Ltd.