Showing papers in "Journal of The Chemical Society-perkin Transactions 1 in 1968"

Natural acetylenes. XXVII. An antifungal acetylenic furanoid keto-ester (wyerone) from shoots of the broad bean (Vicia faba L.; Fam. Papillionaceae).

Abstract: The isolation and determination of the structure of the fungitoxic principle of the broad bean, Vicia faba L., is described. The natural material is the acetylenic keto-ester R[graphic omitted]·CH[graphic omitted]CH·CO2Me (R =cis-EtCH:CH·C⋮C·CO), contaminated with about 2% of the more saturated ketone (R = BuC⋮C·CO). In addition, the alcohol (R =cis-EtCH:CH·C⋮C·CHOH) was found in the shoot extract. These compounds, as well as the lower homologue (R =cis-MeCH:CH·C⋮C·CO), its trans-isomer, the aldehyde (R = OCH·C⋮C), the alcohol (R = HO·CH2·C⋮C), and the close thiophen analogue MeCH[graphic omitted]CH·C⋮C·CO·[graphic omitted]·CH[graphic omitted]CH·CO2Me were synthesised, and their fungitoxic properties were compared.

The total synthesis of (±)-ochotensine and related compounds

Abstract: The total synthesis of racemic forms of ochotensine (I), ochotensimine (II), and analogous compounds (III) and (IV), which are isomeric with the respective alkaloids at the positions of the methylenedioxy-groups, is described.

A new cinnoline synthesis. VI. 4-Mercaptocinnolines.

Abstract: 4-Mercaptocinnolines are obtained in good yield from the 4-hydroxy-compounds by reaction with phosphorus pentasulphide in pyridine. The corresponding amines are prepared readily from the mercapto-compounds by treatment with ammonia or primary amines. The amination reaction fails with nitro-4-mercaptocinnolines. The reaction of the 4-mercapto-derivatives with hydrazine, methylating agents, and Raney nickel is described. Treatment of 6-chloro-4-mercaptocinnoline with chlorine in acetic acid gave a good yield of 4,6-dichlorocinnoline and not the expected 4-sulphonyl chloride.