Conversion of Epoxides to 1,3-Dioxolanes Catalyzed by Tin(II) Chloride

Abstract

Anhydrous tin(II) chloride is an efficient catalyst for the reaction of epoxides with acetone to prepare 2,2-dimethyl-1,3-dioxolanes (acetonides) in good to excellent yields. Mono-, di-, and trisubstituted epoxides participate equally well in this diastereospecific reaction. The use of single enantiomer epoxides under the reported conditions results in significant erosion of optical activity.

Synthesis of the Tetracyclic Framework of the Erythrina Alkaloids Using a [4 + 2]-Cycloaddition/Rh(I)-Catalyzed Cascade of 2-Imidofurans

“…47 In contrast to other members of the lycorine (38) family such as dihydrolycorine (39), lycoricidine (40), pancratistatin (41), only a limited number of syntheses of zephranthine 48 (42) have been carried out and there are no reports dealing with the synthesis of the stereoisomeric epi-zephyrantine (9). Dioxolane 8 was readily available from the oxabicyclic adduct 5b via an acid induced cleavage of boronate 43 to first produce the corresponding diol followed by a subsequent reaction with 2,2-dimethoxypropane.…”

Synthesis of Acetonides from Epoxides Catalyzed by Erbium(III) Triflate

“…Since the 1930s, oxiranes were demonstrated to react with carbonyl compounds to give dioxolanes in low to moderate yields, [3] but only recently has this reaction received increased interest among organic chemists. BF 3 is the most successfully employed catalyst for this reaction, [4] however, SnCl 4 , [3,5] TiCl 4 , [6] TiCl 3 (OTf) and TiO(TFA) 2 , [7] tetracyanoethylene, [8] CuSO 4 , [9] zeolites, [10] CH 3 ReO 3 , [11] K10-montmorillonite, [12] [Cp*Ir (NCMe) 3 ] 2 þ , [13] RuCl 3 , [14] bismuth(III) salts, [15] 2,4,4,6-tetrabromo-2,5-cyclohexadienone, [16] tin(IV) tetraphenylporphyrin perchlorate, [17] K 5 CoW 12 O 40 · 3 H 2 O, [18] and SnCl 2 , [19] have also been used with varying degrees of success pertaining to yield and selectivity. However, many of these catalysts are rather strong Lewis acids and are incompatible with other functional or protecting groups.…”

Heteropolyacid‐catalyzed Reaction of Epoxides with Ketones: Efficient Synthesis of 1,3‐Dioxolane Derivatives

“…Therefore, the more convenient and easily handled synthetic method for 1,3-dioxolanes through the reaction of epoxide with aldehyde or ketone has also been developed, and a variety of catalysts have shown good catalytic activity for such type reaction. 4 On the other hand, heteropolyacid (HPA) as acidic catalyst has been widely used in organic synthetic reactions, 5 but there was no report on the catalytic performance of heteropolyacids in the reaction of epoxides with carbonyl compounds to afford 1,3-dioxolanes. Therefore, in this paper, we report the application of HPA as catalysts in the reactions of epoxides with ketones to develop an alternative catalytic procedure for the synthesis of 1,3-dioxolanes.…”

“…The reaction of 1a with an equivalent of cyclohexanone and benzophenone in CH 2 Cl 2 at ambient temperature for 2 h produced the corresponding 2-chloromethyl-1,4-dioxa-spiro [4,5]decane (2b) and 4-chloromethyl-2,2-diphenyl-1,3-dioxolane (2c) in 96% and 71% GC yields, respectively ( Table 2, Entries 1 and 2). The formation of 2c in somewhat low yield might be partly due to the steric hindrance of phenyl groups of benzophenone.…”

“…also afforded a high yield of 2,2-dimethyl-4-phenyl-1,3-dioxolane (2d) (89% GC yield) ( Table 2, Entry 3). However, in order to achieve the satisfactory yields of 2-phenyl-1,4-dioxa-spiro [4,5]decane (2e) or 2,2-diphenyl-4-phenyl-1,3-dioxolane (2f), it required to use 3 equiv. of cyclohexanone or benzophenone to react with 1b in CH 2 Cl 2 (Table 2, Entries 4 and 5).…”