Butane-1,2-diol, 3,4-epoxy

Several other epoxy resins have been used in literature fracture studies. Chang et al. used a diglycidyl ether of butane diol resin (DGEB) to prepare... 

Fig 11 a-c Epoxy resins used to study epoxy network fracture, (a) DGEBA (diglycidyl ether of Bisphenol A) (b) DGEB (diglycidyl ether of butane diol (c) TGDDM (teraglycidyl of diaminodi-phenyl methane)... 

As an alternative route to the sesquicarane-type sesquiterpenoids, Hortmann and Ong have examined the carbanionic opening of the epoxy-ester (70) derived from perillaldehyde (71). The two products of this reaction are (72) and (73) in the ratio 3 1. Further elaborations of these two compounds have still to be carried out. Plattner and Rapoport have now reported the preparation of both (+)- and (— )-sirenin. This was accomplished by preparative g.l.c. separation of the two diastereoisomeric pairs of ketals derived from the synthetic ketone (74) and D-( —)- and L-( -1- )-butane-2,3-diols. Synthetic procedures for the conversion of racemic (74) into both racemic sirenin and racemic sesquicarene had already been developed. Furthermore, these authors have firmly established by chemical correlation and c.d. studies that naturally-occurring sirenin and sesquicarene have the same absolute stereochemistry, i.e. (75) and (76) respectively. 

A flexible route was developed. Commencing with racemic epoxy tosylate and mono-protected butane-l,2-diol, the synthesis of the precursor proceeded smoothly through several intermediates (Scheme 83) and finally yielded the desired acyclic precursor 323. When compound 323 was added to a solution of Pd2(dba)3-CHCl3 and DPPE or P(OEt)3 ligand, the nine-membered rings 324 and 325 were formed in 71-88% overall yield. Stereocontrol of all three chiral centers has therefore been accomplished in the key steps. 

Optimal conditions for the precipitation of starch xanthate from sodium starch xanthate as the zinc salt have been determined as a xanthate degree of substitution greater than 0.02 and a zinc ion concentration in solution between 0.005 and 0.015 M. Other properties of the starch xanthates were also reported. Aqueous solutions of starch xanthate, butane-2,3-diol dixanthate and alkali-gelatinized starch have been treated with butane-2,3-diol diglycidyl ether and other diepoxides to produce viscous gels. Epoxy resins also reacted with xanthate to form viscous gels. Solids were precipitated from the gels and their compositions deduced from their elemental contents and infrared spectra. 

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