Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• thietane backbones developed during 1966 to 2019. Keywords: cycloaddition; cyclization; ring contraction; ring expansion; thietane; thiotherification; Review 1. Introduction Thietanes are a class of important aliphatic four-membered thiaheterocycles. Some simple alkyl and dialkyl thietanes are components

• of anal gland secretions of the stoat [1] and the ferret [2]. Some pharmaceutical and biological thietane-containing compounds include thiaanalogue thietanose nucleosides 1 and 2 [3][4], and the spiroannulated glyco-thietane nucleoside 3 [5] of the antiviral (anti-HIV and HSV) drug oxetanocin A, the

• miscellaneous methods for the synthesis of various thietane derivatives. A special focus is on the construction of the thietane ring, excluding methods for the simple modifications of the thietane rings and their side chains [26][27][28][29][30][31]. 2. Synthesis via cyclic thioetherifications 2.1 Synthesis via

Glycosylation reactions mediated by hypervalent iodine: application to the synthesis of nucleosides and carbohydrates

• Yuichi Yoshimura,
• Hideaki Wakamatsu,
• Yoshihiro Natori,
• Yukako Saito and
• Noriaki Minakawa

Beilstein J. Org. Chem. 2018, 14, 1595–1618, doi:10.3762/bjoc.14.137

• thietane nucleosides [47]. The substrate of the coupling reaction was prepared as shown in Scheme 6 starting from benzyloxyacetaldehyde (50). When a hypervalent iodine reagent was used for glycosylation with a diastereomeric mixture of sulfide 53, the reaction stereoselectively gave the ring-expanded

• nucleoside 54 in 30% yield, but did not give the desired thietane nucleoside at all (Scheme 6). Considered that the ring-expansion occurred in the absence of the hypervalent iodine reagent, the Nishizono and co-workers speculated that the reaction mechanism was as shown in Scheme 7. First, the Lewis acid

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• , no starting carbazole was found in the reaction mixture after 2 hours (NMR). This reaction led to the selective formation of thietane 3e, isolated in 67% yield (Scheme 3). The structure of 3e was established by single crystal X-ray diffraction (Figure 2). Interestingly, the 19F and 1H NMR spectra of

• (25 °C, 48 h) unexpectedly led to the formation of thione 5 (rather than the corresponding thietane) as a sole product (NMR, Scheme 4). Thione 5 was isolated in 48–50% yield and its structure was established by single crystal X-ray diffraction (Figure 3). At elevated temperature, the reaction of 4

Acid catalyzed cyclodimerization of 2,2-bis(trifluoromethyl)-4-alkoxy-oxetanes and -thietanes. Synthesis of 2,2,6,6-tetrakis(trifluoromethyl)-4,8-dialkoxy-1,5-dioxocanes and 3,3,7,7-tetrakis(trifluoromethyl)-9-oxa-2,6-dithia-bicyclo[3.3.1]nonane

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2010, 6, No. 46, doi:10.3762/bjoc.6.46

• C2H5O) include the formation of 4-(4,4-bis(trifluoromethyl)thietan-2-yloxy)-2,2-bis(trifluoromethyl)thietane on treatment with H2SO4 [4], thiophilic ring opening by the action of alkyl magnesium or lithium reagents [4], the recently reported oxidation with selective formation of the corresponding S

• ” addition of the alcohol to the oxetane cannot be ruled out at this point. Despite the structural similarity shared with oxetanes, thietanes 4a–c display a totally different reactivity (Scheme 6, Scheme 7). For example, no reaction was detected between thietane 4a and an excess of either methanol or

• a combination of 1H, 19F NMR, mass spectrometry and elemental analysis data, the structure of 4-[4,4-bis(trifluoromethyl)thietan-2-yloxy]-2,2-bis(trifluoromethyl)thietane 5a was proposed for that product [4]. In order to clarify this result, thietane 4c (R = C2H5) was treated with H2SO4 (Scheme 7