Cyclopropane, 1 -phenylthio-1 - synthesis

Finally, l-(l -hy(boxyalkyl)-l-(methylseleno)cyclopropanes and some rare phenylseleno analogs belonging to the phenylct inol series produce cyclobutanones on reaction with p-toluenesulfonic acid in a similar manner to the phenylthio analogs. This reaction has allowed the synthesis of a large variety of cyclobutanones, induing those that are polyalkylated (Scheme 163 f ),J2.77.>s9.> ),i99 ajyj substituted or vinyl substituted (Scheme 132, a Scheme 186), by selective migration of the more-substituted carbon (Scheme 163, compare h with f).i2.77,i60... 

A further interesting example is the use of l,l-di(phenylthio)med)yllithium to open an epoxide followed by a Grob fragmentation process as shown in Scheme 56 (entry b). The reaction of 1,1-di-(thio)methyllithium with epoxides has also been used - in the one-pot synthesis of l,l-di(thio)cyclopropanes involving an intramolecular cyclization of the 7-tosyloxydi(phenylthio)alkylli-thium. This intramolecular alkylation reaction proceeds even more efficiently than its intermolecular version, and allows the synthesis of a large variety of l,l-di(thio)cyclopTDpanes from 3-chloro- and 3-phenylthio-l,l-di(thio)alkanes and n-butyllithium in THF (Scheme 57 and Scheme 58). 

Table 13. Synthesis of Cyclopropanes Using Phenylthio-Stabilized Nucleophiles49...

The novel reagents which have been introduced for the synthesis of alkylidene cyclopropanes from (P-hydroxyalkyl) methylselenides proved particularly efficient for the synthesis of a large variety of olefins, including other alkylidene cycloalkanes . PI3 or PjI /NEtj are also to transform (p-hydroxyalkyl) sulfides to olefins but Instead lead to a stable l-(l-phenylthio)-l-(iodomethyl) cyclopropane starting from l-(l-phenylthio)-(hydroxymethyl)cyclopropane (scheme 46) The reaction of... 

Synthesis of Cyclobutanes. t-Chloroperbenzoic acid oxidation of l-phenylthio-l-(trimethylsilyl)cyclopropane furnishes... 

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