PROCEDE DE PREPARATION DE DERIVES DU CYCLOPENTANE

1467813 Prostaglandins MAY & BAKER Ltd 17 May 1974 [22 May 1973] 24473/73 Addition to 1398072 Headings C2C and C2P The invention comprises a process for preparing compounds of Formula IX wherein R 1 is C 1-10 alkyl optionally substituted by alkoxy, or C 5-7 cycloalkyl or adamentyl; R 5 is H or alkyl, n is 5 to 8; and A is =C(OR 6 ) 2 or =C=NOR 8 , wherein the symbols R 7 are identical alkyl groups or together form an ethylene linkage optionally substituted by identical alkyl radicals on each chain; and R 8 is alkyl by reacting aldehydes of the Formula III with phosphonates of the formula wherein R 12 is C 1-4 alkyl, in the presence of bases, the conversion of compounds of Formula IX so obtained into compounds of Formula XII by oxidizing the hydroxymethyl groups to carboxy groups, reducing the oxo group in the resulting cyclopentane carboxylic acids to hydroxy groups and converting the acetal or oximino groups A in the resulting (hydroxyalkenyl)cyclopentanealkanoic acids to carbonyl groups by known methods, and certain compounds falling within the scope of Formula I in patent Specification No. 1,398,072 but not specifically described therein. The following intermediates are also prepared: 1 - chloro - 3 - propylheptan - 2 - ene; 1 - chloro- 3,3 - dimethylheptan - 2 - one; 1 - chloro - 3- propoxyacetone; 1 - chloro - 3 - (1 - methylpropoxy)acetone; 1 - chloro - 3 - isopropoxyacetone; 4 - chloroacetylheptane; and 1- chloro-4-ethoxybutan-2-one. Phosphoranes of the formula are prepared reacting compounds of the formula HalCH 2 COR 1 , wherein Hal is Br or Cl with triphenylphosphine followed by reaction of the resulting phosphonium halides with inorganic bases. Phosphonates of the formula are prepared by reacting dimethyl methylphosphonate with esters of the formula wherein R 13 is ethyl. Pharmaceutical compositions, suitable for oral, parenteral, vaginal or rectal administration, contain the above novel prostaglandins or non-toxic salts thereof together with pharmaceutical carriers and coatings. The compounds possess prostaglandin-like pharmacological properties.