Stereoselective Total Synthesis of Bengamide E from Glyceraldehyde Acetonide and a Nonracemic γ-Alkoxy Allylic Stannane

Article abstract of DOI:10.1021/jo00075a017

The synthesis of bengamide E (30) was achieved starting from the furan adduct 1 of (R)-glyceraldehyde acetonide.The key step entailed MgBr2-promoted addition of the (S)-γ-alkoxy allylic stannane (S)-25 to the aldehyde 8 obtained from the oxidation product of furan 1 after protection as the methyl ether.The adduct of stannane (S)-25 and aldehyde 8, a 1:1 mixture of hydroxy ester 27 and lactone 28 was converted to bengamide E by aminolysis with (S)-2-aminocaprolactam and subsequent debenzylation with Li in NH3.