Butadienyl sulphoxides

Butadienyl sulphoxides may be used as diene compounds in the Diels-Alder cycloadditions. For example, butadienyl phenyl sulphoxide 571 gives a mixture of diastereoisomeric sulphoxides 573 upon heating with an equimolar amount of N-methyl tetrahydrobenzindole 572672 (equation 364). 

Bunnett and Olsen equation 566 Butadienyl sulphones, reactions of 644, 652 Butadienyl sulphoxides reactions of 360 synthesis of 246, 279... 

Bis(4-hydroxyphenyl) sulphoxides butadienyl - see Butadienyl sulphoxides carbamoyl - see Carbamoyl sulphoxides chiral - see Chiral sulphoxides complexes of 567-573 conformational analysis of 84-89 cyclic - see Cyclic sulphoxides cyclopentanone - see Cyclopentanone sulphoxides... 

Butadienyl sulphoxides act as excellent Michael acceptors for nucleophilic acylating agents, particularly lithiated cyanohydrin ethers." The resulting allylic anions may be alkylated, and simple hydrolyses complete an efficient synthesis of dienones [equation (30)]. 

Oxidation of phenyl hexyl sulphide with sodium metaperiodate gave also only a trace amount of the corresponding sulphoxide72. On the other hand, Hall and coworkers73 prepared benzylpenicillin and phenoxymethyl penicillin sulphoxides from the corresponding benzyl esters by oxidation with sodium metaperiodate in dioxane solution with a phosphate buffer. A general procedure for the synthesis of penicillin sulphoxides was reported later by Essery and coworkers74 which consists in the direct oxidation of penicillins or their salts with sodium metaperiodate in aqueous solution at pH 6.5-7.0. 1-Butadienyl phenyl sulphoxide 4475 and a-phosphoryl sulphoxides 4576 were also prepared by the same procedure. 

A combination of [4 + 2] cycloaddition and [2,3]-sigmatropic rearrangement has been used with effect in the synthesis of hasubanan derivatives. Thus the 1-butadienyl phenyl sulphoxide (456) reacts with the enamine (457) to yield (458) as a mixture of diastereoisomeric sulphoxides. Heating (458) in the presence of a thiophilic species drives the equilibrium over to the sulphenate ([2,3]-sigmatropic shift) as the latter is converted into the amino-alcohol (459). This annelation sequence may also be used with electron-deficient dienophiles by employing 1-butadienyl phenyl sulphide (460). ... 

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