Isoprene → 2-Methyl-1-morpholino-2,5-heptadiene

Participants

Reaction Steps

In a much slower reaction than Example 19, Z-1-bromopropene, isoprene and morpholine gave 2-methyl-1-morpholino-2,5-heptadiene in 40% yield along with higher boiling unidentified products and polymers. The major point of interest in this Example was to determine whether or not the stereochemistry of the Z-1-bromopropene was retained in the product. The product appeared homogeneous by GLC (gas liquid chromatography) and NMR (nuclear magnetic resonance); however, IR (infrared) showed bands characteristic of both cis and trans olefinic groups. Therefore, the product may be a mixture of isomers. Aside from the stereochemistry with respect to the double bonds, the structure can be assigned conclusively from the NMR spectrum. The addition of the 1-propenyl group, therefore, was completely regio-selective, adding to the terminal carbon of the less-substituted double bond of the isoprene. This contrasts with the mixture of positional isomers obtained when this halide was added to 1-hexene (refer Example 4, supra).

Provenance & Evidence