str8 the compound of formula vi can then be converted to a compound having the formula str9 e g by reduction in tetrahydrofuran with a borohydride like sodium borohydride or zinc borohydride treatment of the compound of formula vii with diisobutylaluminum hydride or diisobutylborane yields a compound having the formula str10 which then is submitted to wittig reaction conditions e g with an alkoxymethyl triphenylphosphonium halide like methoxymethyl triphenylphosphonium chloride in the presence of an alkali metal alkylamide like lithium diisopropylamide a lithium alkyl like n butyl lithium in an inert organic medium like toluene tetrahydrofuran or the like at a temperature in the range of about 10 u00b0 to 25 u00b0 c this product of formula ix is acylated e g with an acylpyridinium halide like n acetylpyridinium chloride in the presence of an acid acceptor like pyridine oxidized with an oxidizing agent like mercuric acetate in an organic medium like tetrahydrofuran then demetalated with a reducing agent like potassium iodide to yield a product having the formula str12 alternatively the product of formula ix can be treated with an acid like formic acid or trifluoroacetic acid to yield a product having the formula str13 these products of formulas x or xi are subjected to a.