475091-17-9Relevant articles and documents
Applications of vinylogous Mannich reactions. Total synthesis of the angiotensin converting enzyme inhibitor (-)-A58365A
Reichelt, Andreas,Bur, Scott K,Martin, Stephen F
, p. 6323 - 6328 (2002)
A concise enantiospecific synthesis of the angiotensin converting enzyme inhibitor (-)-A58365A (7) has been achieved following a strategy in which a vinylogous Mannich reaction and a lactone-lactam rearrangement served as the key transformations. The trimethylsilyloxyfuran derived from 25, which was prepared from the known sulfoxide 16, served as the nucleophilic partner in a vinylogous Mannich reaction with the chiral N-acyliminium ion that was generated in situ from the aminal 26. Addition of a further quantity of TMSOTf cleaved the N-Boc group from the adducts 27 to give a mixture of diastereomeric amino butenolides 28. Treatment of this mixture with LiOMe/MeOH furnished 10, and acid-catalyzed hydrolysis of the methyl ester groups delivered (-)-A58365A in 37% overall yield over the longest linear sequence of eight steps.
