prostaglandin analogs useful in treating thrombotic and vasospastic disease having the structural formula ## str1 ## wherein : m is 1 , 2 , or 3 ; n is 0 , 1 , 2 or 3 ; r is co 2 r &# 39 ;, ch 2 oh , conhso 2 r hu 3 , conhr 4 , or -- ch 2 - 5 - tetrazolyl ; r &# 39 ; is hydrogen , alkyl , or alkali metal ; x is o or nh ; y is -- o --, a single bond or vinylene , except that y cannot be -- o -- when n is 0 and if y is vinylene , then n = 0 ; ## str2 ## and the remaining symbols are as defined in the specification .