L,3-Dithian-2-one

Organotin 1,2-dithiolate complexes were featured in many studies the ligands used include aliphatic derivatives, e.g. ethane-1,2-dithiolate -SCH2CH2S-(EDT), -SCH2CHMeS-, alkenyl derivatives, e.g. -SCH=CHS-, maleonitriledithiolate (MNT), aryl derivatives, 1,2--SC6H4S (BDT) and toluene-3,4-dithiolate (TDT), as well as heterocyclic derivatives, l,3-dithiane-2-one-4,5-dithiolate (DMIO) and l,3-dithiane-2-thione-4,5-dithiolate (DMIT)191. 

Dithians and 1,4-Dithians.—Equimolar amounts of propane-1,3-dithiol and phosgene condensed to give a high yield of l,3-dithian-2-one by a procedure which is a considerable improvement on earlier methods.A 1,3-dithian is also obtained when an aldehyde is condensed with a 1,3-dimercaptoacetone (Scheme 10) 300 mechanism of the formation of 2,3-dihydro-1,4-dithians (323) from a-halogeno-acetals (Scheme 11) appears to involve the carbonium ion (322). ... 

During studies on the interaction between sulfur donors and suitable acceptors, the solid-state structure of the charge-transfer adduct l,3-dithiane-2-thione- -diiodine 111 was investigated <1999IC4626> the CS3 moiety is planar, the I2 molecule lies in the same plane with the first iodine atom separated by 2.755 A and the I-I vector is practically co-linear with the S-I one. The I-I bond length is slightly elongated with respect to a free iodine molecule. 

The cyclodextrin-supported cleavage of 1,3-oxathianes with IBX (cf Scheme 76, Section 8.11.6.4.6) <2006SC3771>, as well as the copper-catalyzed aminolysis of 1,3-dithianes <2006OL2547> has been published. l,3-Dioxane-2-ones readily undergo a Grob fragmentation (Equation 100) <2006CC4303>. This reaction is catalyzed by Ni- (24-99% yield) or by Pd-complexes (42-93% yield). 

Photolysis of l,3-dithian-5-ones, for example, 360, and 3-methyl-5-thiacyclo-hex-2-ene-l-one, 361, gives 3-thietanones. A 3-thietanone intermediate was suggested in the photolysis of 3-thiatetralone. Photolysis of 8-thiabicyclo-[3.2.1.]-3-octene-2,6-dione gives a 3-thietanone, 8-thiabicyclo[4.1.1]-4-octene-3,7-dione. Thermolysis of the a-diazoketone 362 gives the 2-exomethylene derivative 363. ... 

Reaction of lithiodithianes with acyl chlorides, esters or nitriles leads to the fOTination 1,2-dicarbonyl compounds in which one of the carbonyl groups is protected as the thioacetal. d76043j44 Optically active amino ketones of type (69) are inepared via acylation of dithiane with an oxazoline-protected (5)-serine methyl ester (Scheme 41). Optically active (5)-2-alkoxy-l-(l,3-dithian-2-yl)-l-propanones were prepaid by the reaction of the corresponding methyl (5)-lactate with 2-lithio-l,3-enantioselective synthesis of (-)-trachelanthic acid. Enantioselective synthesis of L-glyceraldehyde involves the acylation of a dithiane glycolic acid derivative followed by bikers yeast mediated reduction. ... 

In contrast to 2-phenyl-l,3-dioxan-5-one, where nucleophiles add, regardless of their size, from the axial side of the carbonyl group, the same nucleophiles add to 2-phenyl-l,3-dithian-5-one exclusively from the equatorial side, to yield (165). A ring-expansion reaction has been observed when 2-methy 1-2-ethyl-1,3-dithiolan was brominated, giving the dithiin (166). ... 

Methoxytrimethylsilane, 123 Methyl acetoacetate, 92 Methyl bromoacetate, 107 Methyl 11-hydroxyundecanoate, 58 Methyl lithium, 27,28 Methyl 10-undecenoate, 58 2-Methyl-l, 3-dithiane, 81 (fl/ ,5 )-Methyl-3-phenyldiniethyl-silyl-3-phenylpropionic acid, 53-4 2-Methyl-3-Phenylprop-2-cnal, 111 2-Methyl 2-lrimethylsilyl-1,3-dithiane, 81 2-Methyl-l-(trimcthylsilyloxy)cyclo-hex-l-ene, 100,109 2-Melhyl-l-lrimethylsilyloxy)cyclo-hcx-6-enc, 100 2-Methyl-2-trimethylsilyloxy-pentan-3-one, 132 2-Methylacetophenone, 42-3 2-Methylbutyraldehyde, 85 2-Methylcyclohexanone, 99,100 2-Methylcyclohexanone, 131 4-Methyldec-4-ene, 67-8 Methylenation, 63 2-Methylpropen-l-ol, 131 Methyltriphenylphosphonium bromide, 27 Michael addition, 85 Monohydridosilanes, 128 Monohydroalumination, 29... 

The Homer - Emmons reagent (52) is effective in the one carbon homologation of ketones possessing acidic a-hydrogen atoms <96SL875> and electron-deficient alkenes add to 2-phenylseleno-l,3-dithiane in a photo-initiated heteroatom stabilised radical atom transfer process, giving products of considerable synthetic potential <96TL2743>. 

The following is an example for a sequential one-pot epoxide formation/nucleophilic opening process using (S)-4-(benzyloxy)-l,2-butanediol, iV-(p-tohienesulfonyl)-imida-zole, and 2-lithio-l,3-dithiane ... 

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