General asymmetric synthesis of hydroxymethylene and hydroxyethylene peptide isosteres

Article abstract of DOI:10.1016/S0040-4020(98)00495-5

The Lewis acid-promoted coupling reactions of (5R, 6S)-2-acetoxy-4- (benzyloxycarbonyl)-5,6-diphenyl-2,3,5,6-tetrahydro-4H-1,4-oxazines (11a-e, and 21), which are prepared easily from (+)-(5R, 6S)-4(benzyloxycarbonyl)- 5,6-diphenyl-2,3,5,6-tetrahydro-4H-1,4-oxazin-2-one (9), with allyltrimethylsilane proceeded to give the corresponding coupling products with moderate to excellent stereoselectivity in good yields. These coupling products (13a, b, and d) were converted to hydroxymethylene-(25a, b, and d) and hydroxyethylene (28) peptide isosteres.