4- 2 phenylthio 1 butene, synthesis

A total synthesis of squalene and lower terpenes" using the functionalized isoprene 2-hydroxymethyl-4-phenylthio-l-butene (21) has been recently reported. The starting material (21) has three functionalities an allylic alcohol allowing two-carbon elongation by Claisen rearrangement a homoallyl phenyl... 

Jeong et al. also reported on allene synthesis via addition-elimination sequence as a key reaction, starting from 3,3-bis(phenylthio)-l,l,l,2,2-pentafluorobutane 64 (Scheme 26.59). Thus, treatment of 64 with an excess amount of aryllithium reagents in Et20 at low to room temperature for 1-6 hours gives 2-aryl-1,1,1-trilluoro-3-phenylthio-2-butene 65 in 80-96% yields. Bromination of 65 with NBS in MeCN at reflux temperature for 1-7 hours, followed by wCPBA oxidation in CH2CI2 at the reflux temperature for 1-12 hours, results in the formation of 1-aryl-l-trifluoro-methylallenes 66 in 74-96% yields. 

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