| http://www.w3.org/ns/prov#value | - (2) Alternatively, a compound of formula III can be reacted as follows: a compound of formula III wherein Ya is hydrogen or halogen, iodine or especially chlorine or bromine and Xa is halogen (preferred) or acyloxy, while Ra and Rb are as defined for compounds of formula III, is converted in the presence of a base, with elimination of hydrohalic acid HX, into an olefin of formula VII
|
