Cis-l,3-pentadiene

Figure 19.7. Cyclic batch elution chromatography obtaining high product purity and high throughput by using incomplete resolution (overlapping bands) and recycling the mixed fraction (mf) to the feedstock (a) Control of band separation and cut points determines fractional impurities t mij mr and Ami /mr2-<4l)> (b) Chromatogram for separation of pure ds- and trans- 1,3-pentadiene. Components 1, isoprene 2, trans- 1,3-pentadiene 3, cis-l,3-pentadiene 4, cyclo-pentadiene. Component 1 is eluted at almost the same time as component 4 of the...

However, treatment of cis-l,3-pentadiene with Fe(CO)5 leads to formation of the hydride intermediate as shown for the conversion of 1,4-pentadiene to the borohydride treatment of 7r-pentadienyliron tricarbonyl cation (see below). 

Addition of It to the isomeric 1,3-pentadienes and other nonsymmetrically substituted dienes occurs selectively at the more substituted diene double bond (106). For example, the reaction of 1-t with cis-l,3-pentadiene yields adducts 51, 52, and 53 (mixture of stereoisomers) in the ratio 3.3 1.2 1. 

The complex of cis-l,3-pentadiene can be indirectly obtained by reaction of NaBH4 with the ew-pentadienyl cation [cw-C5H7Fe(CO)3]+ (81), which is prepared by interaction of /raws-l,3-pentadiene-5-ol with Fe(CO)5 and treatment with HCIO4 (387). The product is a mixture... 

In 1962 Rinehart et al. [30] and Canale et al. [31] independently reported on the rhodium-catalysed emulsion polymerization of butadiene to a high trans-, A polymer utilizing sodium dodecylbenzenesulfonate as an emulsifer. More than 10 years later Entezami et al. [32] showed that trans- and cis-l,3-pentadiene can be polymerized in emulsion using RhCls as a catalyst and sodium dodecylbenzenesulfonate as a surfactant. Unfortunately, these authors did not mention latex particle sizes. Finally, ethylene can also be polymerized in emulsion [33] using a rhodium-based catalyst. 

These studies were followed by the asymmetric polymerization of similar trans- and cis-l,3-pentadienes within the channels of two steroids of deoxy-cholic acid (DCA) and apocholic acid (ACA) [12-14]. The packing of the two... 

The quantum yield for formation of 3-methylcyclobutene from trans-1,3-pentadiene is 10 times greater than for the cyclization of cis-l,3-pentadiene. Can you offer an explanation ... 

Interestingly, sequential migration-Diels-Alder reactions of tert-butyldioxy die-none 63 in the presence of cis-l, 3-pentadiene gave cis-fused octahydroanthraquinone 64 stereoselectively (73%) (Eq. (7.76)). 

---