Sulfones from ketones

The condensation of sulfonyl chlorides with enamines (452,453) derived from aldehydes and ketones has led to four-membered-ring sulfones, presumably through such intermediates (454-464). Open sulfonation products have also been obtained, particularly from ketone-derived enamines and from a-disubstituted sulfonyl chlorides. 

Recently, the pyrazole group containing bisphenols have been synthesized from activated aromatic dihalides and 3,5-bis (4-hydroxy phenyl)-4-phenyl pyrazole or 3,5-bis(4-hydroxy phenyl)-1,4-diphenyl pyrazole. A novel synthesis of imido aryl containing bisphenols has been reported [32]. N-substituted l,4-bis(4-hydroxy phenyl)-2,3-naphthalimides were prepared from phenolphthalein and copolymerized with aromatic sulfone or ketone difluorides to obtain the poly(imidoaryl ether) sulfones/ ketones. 

The procedure described here provides a stereospecific synthesis of (E)- and (Z)-fluoroalkenes from the corresponding (E)- and (Z)-fluorovinyl sulfones. Fluorovinyl sulfones obtained from ketones are, in most cases, readily separable into (E) and (Z) isomers either by crystallization or by chromatography.4 In the example described, only the (E)-fluorovinyl sulfone 1 is formed (which is converted into the (Z)-fluoroalkene 3 with complete retention of configuration). The reaction sequence has been used for the stereospecific synthesis of fluoroalkene nucleosides5 as well as for... 

With both building blocks 103 and 109 in hand, the total synthesis of lb was completed as shown in Scheme 17. Coupling of acid 103 and alcohol 109 under Yamaguchi conditions to give ester 110 and subsequent desilylation followed by chemoselective oxidation provided hydroxy acid 111. Lactonization of the 2-thiopyridyl ester derived from 111 in the presence of cupric bromide produced the macrodiolide 112 in 62% yield, which was finally converted to pamamycin-607 (lb) via one-pot azide reduction/double reductive AT-methylation. In summary, 36 steps were necessary to accomplish the synthesis of lb from alcohols 88 and 104, sulfone 91, ketone 93, and iodide rac-97. 

Other dipolarophiles have been tested leading to pyrrolidines (from vinyl sulfones),219 oxazolidines (from ketones) and thiazolidine (from a thioketone) in moderate to good yields. Noteworthy is the isolation of two adducts from ethoxycrotonaldehyde a pyrrolidine carbaldehyde implying cycloaddition onto the ethylenic double bond and an oxazolidine resulting from the cycloaddition on the carbonyl moiety of the dipolarophile.219 438... 

Use of excess alkali metal in liquid ammonia or an amine (generally EtNH2 or ethylenediamine, EDA) is also a widespread procedure used to desulfurize sulEdes, dithioketals and sulfones. - - From the numerous works published, a number of interesting features emerge. Thus desulfurization of sulfides in liquid NH3-THF tolerates esters and ketones, while Li-EtNH2 cleaves the C—S bonds of unsaturated substrates without side reactions (Scheme 1). Sodium in liquid ammonia was found to be a better... 

An alternative route to epoxides from ketones uses a-chloro sulfones and potas-... 

The addition of metalated sulfones to aldehydes or ketones is a reversible reaction and the principal cause of failure in the Julia alkenation results from an unfavorable equilibrium at this stage. The reverse reaction is favored when the P-alkoxy sulfone adduct is sterically encumbered. Adducts derived from ketones are more vulnerable than those derived from aldehydes. Stabilization of the sulfone anion by conjugation with an aromatic ring or chelation with a proximate heteroatom are also important contributors to favoring the reverse reaction. However, by varying the metal counterion, the position of equilibrium can be adjusted. For example, the lithio derivative of the sulfone (61 Scheme 24) failed to... 

Chemiluminescence intensity is affected when dioxetane is replaced from the coordination sphere of the Eu(III) by the other ligand, such as sulfoxides, sulfones or ketones (Scheme 3). This effect allowed us to develop a chemiluminescent procedure to study equilibriums in solutions. If we know stability constant (K ) for the Eu(fod)3-DO complex, we may obtain an equilibrium constant... 

Similarly, it has been reported that hydrocarbons can be obtained from primary amines by treatment of the amine with aqueous sodiumhydroxide andhydroxylamine-O-sulfonic acid (Scheme 10.21) and enamines, obtained from ketones and secondary amines, can be converted to alkenes by reduction with alane (AIH3) (see Coulter, J. M. Lewis, J. W. Lynch, P. P. Tetrahedron, 1968,24,4489) (Equation 10.40). 

---