Singlet oxygen in synthesis. Oxazoles as carbonyl 1,1-dipole synthons.
作者:Harry H. Wasserman、Robert W. DeSimone、Wen-Bin Ho、Keith E. McCarthy、K.Spencer Prowse、Alfred P. Spada
DOI:10.1016/s0040-4039(00)60874-2
日期:1992.11
2,5-Diphenyloxazole has been utilized in a two-step sequence as a carbonyl 1,1-dipole synthon as illustrated by the synthesis of 7-heptanolide, α-benzyloxy δ-valerolactone, and 9-nonanolide. Alkylation of 4-lithio-2,5-diphenyloxazole, followed by singlet oxygen oxidation yields a triamide which undergoes cyclization to the lactone.
如7-庚醇化物,α-苄氧基δ-戊内酯和9-壬醇化物的合成所示,已将2,5-二苯基恶唑按两步顺序用作羰基1,1-偶极合成子。4-锂硫基-2,5-二苯基恶唑的烷基化,然后单线态氧氧化,产生三酰胺,该三酰胺经历环化成内酯。