The synthesis of 4-oxo-9-deoxy-9-azaprostaglandin I2 (23a) and two ω-chain analogues thereof (23c and 23e) is described. The most salient features of the synthetic process used were (a) introduction of the nitrogen functionality at C-9 by [3,3] sigmatropic rearrangement of the trichloroacetamidate 5b to the trichloroacetamide 6, (b) transformation of 6 into the bicyclic lactam 7 with sodium borohydride, (c) stereospecific introduction of the 11α-hydroxyl group via the bromohydrin 8a, and (d) attachment of the α chain by extrusion of sulfur from the thioimidates 20 by the Eschenmoser sulfide contraction process.

No abstract

No abstract

No abstract

Key steps in the synthesis of the title compounds (XII) are the preparation of the amide (III), its transformation to the lactam (IV) by reductive deacylation followed by stereoselective introduction of a hydroxyl group and attachment of the α‐chain to the thiolactam (IX) via formation of a thioether and subsequent Eschenmoser sulfide contraction.