A two step synthesis of the title compounds from easily available star
ting materials is reported. The method involves a Horner-Wadsworth-Emm
ons reaction between beta-ketophosphonates and 1,3-diacetoxy-2-propano
ne, followed by mild acid treatment of the gamma,gamma'-diacetoxyenone
s thus obtained. (C) 1997 Elsevier Science Ltd.