carbon atoms such as formyloxy acetoxy and propionyloxy the term 34 lower alkyl aryl 34 as used herein denotes alkyl aryl groups wherein the alkyl and aryl moieties are as defined above the initial step in the preparation of the compound of formula 1 involves the preparation of a compound of the following formula str6 wherein r 1 r 2 r 3 and r 4 are as previously defined and q is formyl str7 where r 11 is lower alkyl and ch 2 or 10 where r 10 is hydrogen or lower acyl which comprises reacting a compound having the formula str8 wherein r 1 r 2 r 3 and r 4 are as previously defined with a compound having the formula str9 wherein q is as defined above the above reaction may be conducted in the presence or absence of solvent at temperatures varying from about 15 u00b0 c to about 200 u00b0 c if it is desired to employ a solvent any inert organic solvent may be used typical solvents that may be employed are aliphatic hydrocarbons such as pentane hexane heptane octane and the like aromatic hydrocarbons such as benzene xylene toluene naphthalene and the like halogenated hydrocarbons such as methylene chloride carbon tetrachloride chlorobenzene and the like amides such as formamide dimethylformamide dmf tetramethylurea hexamethylphosphoric acid triamide ethers such as dioxane anisole and tetrahydrofuran nitriles such as acetonitrile benzonitrile and the like ketones such as acetone cyclohexanone and the like solvents such as dimethylsulfoxide dmso and n methylpyrrolidone may also be employed the above mentioned solvents may be used singly or in combination the diels alder condensation of compounds vi.