2- ethyl phenyl sulfone

Tanaka and coworkers337 reported successful syntheses of aldehydes and ketones using (l-ethoxyethoxy)methyl phenyl sulfone 258 and 1-(1-ethoxyethoxy)ethyl phenyl sulfone 259, as shown in the following scheme. 

Oxo-2-phenyl-ethyl)-phenyl-sulfon und Carbonsaure-halogenid-hydrazonide cyclisieren zu 5-Phenyl-4-phenylsulfonyl-l H-pyrazolen (70-85%)932 ... 

A novel synthetic strategy has been designed using the ring opening of cyclic sulfates 121 and 124 with lithiated /3-(trimethylsilyl)ethyl phenyl sulfone followed by elimination of the silyl and sulfone group. An efficient synthesis of methylene cyclopropanes 123 and 126 (92JOC6344), respectively, is produced (Scheme 31). 

Protection of Phosphates and Phosphonates. 2-Hydroxy ethyl phenyl sulfone (1) has been used to differentially protect phosphate esters for nucleotide synthesis. Thus, reaction of the diphosphate (8) with 1 and l-(mesitylene-2-sulfonyl)-3-nitro 1,2,4-trIazole (MSNT) in pyridine afforded the differentially protected phosphate 9 in very good yield (eq 5). The 2-phenylsulfonylethyl phosphate can be cleaved under mild conditions by treatment with triethylamine. 

Preparative Methods prepared in situ as needed by metalation of ethyl phenyl sulfone with butyllithium or lithium diisopropylamide. 

Terminal epoxides react slowly with sulfonyl carbanions such as the homoenolate equivalent (1) (eq 4). With disubstituted epoxides and cyclic epoxides the reactions are slower still. For example, reaction of the lithio derivative of ethyl phenyl sulfone with cyclopentene oxide occurs in excellent yield (98%) after 10 h reflux in toluene. It has been reported that, in some cases, the addition of a Lewis acid (magnesium bromide, boron trifluoride etherate, 4 titanium tetraisopropoxide, MeOAl(i-Bu)2 ) or HMPA iirproves the yield dramatically. 

Ethylphenyl)-2-phenylethane Ethyl 3-phenylpropanoate Ethyl 3-phenylpropynoate Ethyl phenyl sulfone... 

Bromo-l-propenyl phenyl sulfone (104) can serve as a Michael acceptor to Grignard reagents to give cyclopropyl phenyl sulfones in good yields, (equation 85)70. Cyclopropanes prepared by this method are listed in Table 8. However, with methyl, ethyl or t-butyl... 

Cyclopropyl sulfones were shown to be obtained either by cyclization of y-p-tosyloxy sulfones 232 with base or by treatment of phenylsulfonylacetonitrile 233a or ethyl phenyl sulfonyl acetate 233b with 1,2-dibromoethane in the presence of benzyltriethyl-ammonium chloride (BTEA) and alkali in good yields. Chang and Pinnick synthesized various cyclopropane derivatives 234 upon initial treatment of carbanions derived from cyclopropyl phenyl sulfone with either alkylating agents or a carbonyl compound and subsequent desulfonylation, as shown below. 

The dipolarophile was prepared in a short (three-step) sequence from methyl phenyl sulfone (38% overall yield) and ethyl trifluoroacetate. Desulfonation, followed by reductive N-0 cleavage afforded the syn aminoalcohols [246]. Conjugate additions to the sulfone were described some years earlier [247] more recently, trifluoromethyl pyrroles have been synthesised from the nitro-propene [248]. 

The presence of an NH group is essential, since the Boc-p-amino sulfone derived from Pro could only be coupled with lower yields (-20%). This method is also suitable for the preparation of pseudodipeptides having functionalized side chains such as those of Ser and AsnJ72l The p-oxo sulfone 51, which was obtained by reacting Boc-pAla-OMe with the dilithium anion of methyl phenyl sulfone, cleanly reacted with ethyl bromoacetate to give the p-oxo sulfone 52 (86%). The latter was reduced using LLAIH4, which on reductive elimination produced the over-reduced Boc-Alai)i(CH2—CH2]Gly-OMe isostere (80%). 

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