Dioxoles , synthesis

Thieno[ 1,2,3]diazaborines, dihydro-bromination, 1, 656 deuteration, 1, 658 iodination, 1, 656 nitration, 1, 656 nucleophilic substitution copper-promoted, 1, 658 Thienodiazepines synthesis, 7, 595 Thieno[ 1,2]diazepines synthesis, 7, 598 Thieno[2,3-d][l, 2]diazepines synthesis, 4, 749 Thieno[3,2-d][l,2]diazepines synthesis, 4, 749 Thieno[ 1,3]diazepines synthesis, 7, 607 Thieno[ 1,4]diazepinones as anticonvulsants, 1, 170 Thieno[3,4-d][l,3]dioxol-2-one, 4,6-diphenyl-... 

Ethenediyl carbonate (l,3-dioxol-2-one vinylene carbonate, 417) is a readily available,270 versatile synthon having pronounced dienophilic properties.270-275 Diels-Alder adducts of 417 with 1,4-di-acetoxy-1,3-butadiene and furan were selectively converted into cy-clitols,256 257-275 and also served as precursors of DL-ribose derivatives258 (see Section IV, 2). Another possibility of applying 417 as an equivalent of a 1,2-dihydroxyethane unit has been demonstrated in a synthesis of racemic apiose. Photochemical cycloaddition of 417 to 1,3-diace-toxy-2-propanone (418) gave the oxetane derivative 419, which, on alkaline hydrolysis, afforded DL-apiose (420) in 23% yield.1... 

Diphenylthieno[3,4-d][l,3]dioxol-2-one 5,5-dioxide (304) can serve as an activating agent for peptide synthesis (76AG(E)444). The esters (305) are formed readily on admixture of a carboxylic acid with (304) in an aprotic solvent in the presence of pyridine. The activated esters (305) are stable, crystallizable compounds which react with amines readily to furnish the corresponding amides (Scheme 65). Competition experiments reveal that the esters (305) are more effective acyl transfer agents than the p- and o-nitrophenyl esters often used in peptide synthesis. 

Synthesis of podophillotoxin and related fused compounds containing hydrofuranone and 1,3-dioxole fragments 92S719. 

The ability of furan to undergo both the forward and reverse Diels-Alder reaction has been used to synthesize 1,3-dioxoles, and the reaction appears to have wide applicability. In Scheme 42 the synthesis of 2-phenyl-l,3-dioxole is shown. The key to the process is the dialcohol (119), which is obtained from vinylene carbonate as shown. The dialcohol (119) has the potential of serving as an intermediate for a variety of 2-substituted 1,3-dioxolanes (73JA7161). 

Reaction of the stabilised iodonium ylide 8 with ketones gives the dioxoles 9 <02TL5997> and rhodium catalysed reaction of Me02C-C(=N2)-CF3 with aldehydes similarly gives 10 <02OL2453>. A general synthesis of l,3-dioxol-2-ones has been described... 

Considerable work was done to induce chirality via chiral auxiliaries. Reac tions with aromatic a-ketoesters like phenylglyoxylates 21 and electron-rich al kenes like dioxoles 22 and furan 23 were particularly efficient (Scheme 6). Yield up to 99% and diastereoselectivities higher than 96% have been observed whet 8-phenylmenthol 21a or 2-r-butylcyclohexanol 21b were used as chiral auxiliarie [14-18]. It should be noted that only the exoisomers 24 and 25 were obtained from the reaction of dioxoles 22. Furthermore, the reaction with furan 23 wa regioselective. 24 were suitable intermediates in the synthesis of rare carbohydrate derivatives like branched chain sugars [16], Other heterocyclic compounds liki oxazole 28 [19] and imidazole 29 [20] derivatives as well as acyclic alkenes 3fl 31, and 32 [14,15,21,22] were used as olefinic partners. Numerous cyclohexane derived alcohols [18,21-24] and carbohydrate derivatives [25] were used as chiri... 

A two-step synthesis of cicerfuran was achieved using McMurry cross coupling of 4-benzyloxy-2-hydroxy-benzoaldehyde with 6-methoxybenzo 1 3]-dioxole-5-carbaldehyde, followed by an oxidative cyclization <07JOC10283>. 

Since the publication of the corresponding chapter in CHEC-II(1996) <1996CHEC-II(3)525>, there have been a large number of developments in the chemistry of 1,3-dioxole systems and these have mainly involved 1,3-benzo-dioxoles 1, 1,3-dioxolanes 2, and the isomeric l,3-dioxolan-2-ones 3 and l,3-dioxolan-4-ones 4. There have been specific reviews on the synthesis of 1,3-dioxolium salts 5 <2002SOS(11)13> and the transformations of the 6,8-dioxabicyclo[3.2.1]octane compounds 6 <2003SL1759>. 

A large number of new reports of reactions of this type have appeared, the majority of which involve reaction between a 1,2-diol or equivalent and an aldehyde, ketone, or other component that supplies C-2 of the resulting dioxole ring. Synthesis of aromatic fused dioxoles will be considered first before dioxolanes and dioxolanones. 

Paquette, L.A., Wang, T.-Z., Philippo, C.M.G., and Wang, S., Total synthesis of the cembranoid diterpene lactone (-i-)-cleomeolide. Some remarkable conformational features of nine-membered belts linked in a 2,6-fashion to a methylenecyclohexanc core, J. Am. Chem. Soc., 116, 3367, 1994. Moskva, V.V., and Razumov, A.I., Phosphinic and phosphinous acids. Part 34. Phosphorylated 1,3-dioxolanes, Trans. Kazan. Khim.-Tekhnol. Inst., 34, 273, 1965 Chem. Abstr, 68, 39729y, 1968. Razumov, A.L, and Gurevich, P.A., Synthesis of phosphorylated 1,3-dioxoles, Zh. Obshch. Khim., 38, 944, 1968 J. Gen. Chem. USSR (Engl. Transl.), 38, 909, 1968. 

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