Renin inhibitors, treatments and dipeptide synthesis

Claim 1

A polypeptide analogue of the formula: ##STR64## or the partial sequences: X--A--B--Z--W (V)(i) X--His--A--B--Z--W (V)(ii) X--Phe--His--A--B--Z--W (V)(iii) X-Pro-Phe-His-A-B-Z-W (V)(iv) where: Pro, Phe and His are in substituted form; Pro by OH, Phe by OH, F, Cl, Br or Me, His by Me; or Phe is replaced by pGlu, Phe by Tyr or His by spinacin. X=H; or an N-protecting group; Y=D- or L-His or is absent; A= ##STR65## where the configuration at asymmetric centres * is either R or S, where in VIII the hydroxy group and protected in ether --OR 4 or ester ##STR66## form where R 4 is as given under W below and where R 1 and R 2 , the same or different= i Pro (isopropyl), i Bu (isobutyl) or Bzl (benzyl); R 3 =H or an N-protecting group; B=D- or L-Val Leu or Ile; Z=D- or L-Tyr, Phe, or His; and W=(i)--OH and in protected ester form as --OR 4 where R 4 =lower alkyl C 1 -C 5 ; or (ii)--NH 2 and in protected amide form as --NHR 5 or --N(R 5 ) 2 , wherein R 5 =an N-protecting group; or (iii) an L- or D-serine or L- or D-lysine or arginine and in amide form, or (iv) an amino alcohol residue derived therefrom as such or protected in ester or ether form or Z+W=an alcohol derived from L- or D-Tyr, Phe or His residue and protected in ester or ether form; isosteric links as set out above for A being in free form or in protected form at one or more nitrogen, carboxyl, hydroxy or other reactive groups or in salt form at amino imidazole or carboxyl groups as their physiologically acceptable acid addition salts at basic centres.