Preparation of new nitrogen-bridged heterocycles. 46. Selective formation of 4(1H)-8,8a-dihydro-1,4-thiazino[3,4,5-cd]indolizinone and (E)- 3-(1,3-oxathiol-2-ylidene)-2(3H)-indolizinone derivatives

Article abstract of DOI:10.1248/cpb.46.1866

The reactions of (Z)-3-[mercapto(methylthio)methylene]-2(3H)- indolizinones with bromoacetonitrile and bromoacetates in the presence of a base gave the corresponding 4(1H)-8,8a-dihydro-1,4-thiazino[3,4,5- cd]indolizinone derivatives, but similar treatment of the same compounds with some phenacyl bromides provided a quite different type of product, (E)-3-(5- aryl-1,3-oxathiol-2-ylidene)-2(3h)-indolizinones, in 12-74% yield with the evolution of methanethiol. Interestingly, the reactions of (Z)-3- [mercapto(phenacylthio)methylene]-2(3H)-indolizinones and iodomethane in the presence of a base did not afford the expected (Z)-3-(5-aryl-1,3-oxathiol-2- ylidene)-2(3H)-indolizinones, but gave only the same (E)-isomers in 22-53% yields. The stereochemistry about the C3-C2' double bond in these 3-(5-aryl- 1,3-oxathiol-2-ylidene)-2(3H)-indolizinones was determined to be (E) by X- ray analysis.

Full text of DOI:10.1248/cpb.46.1866

NII-Electronic Library Service

NII-Electronic Library Service

NII-Electronic Library Service

NII-Electronic Library Service

NII-Electronic Library Service

NII-Electronic Library Service