Tals with with alkenes is usually a two opposite (entry(entry ten). According tocalculations, the regioselectivity of reactions of furanic ace- ace10). In accordance with DFT DFT calculations, the regioselectivity of reactions of furanic Lewiswith alkenes is often a C, twoof two though stericcharge interactions amongst the furanethylthioacetal with and alkene favor orthoselectivity, steric variables ZnCl2-catalyzed reaction of aspects promote metaselectivity [32]. and alkeneacid DM4-d6 Microtubule/Tubulin catalysts (entries five). For thepromote trans-Zeatin-d5 site moderate endoselectivity were observed favor orthoselectivity, whilst metaselectivity [32]. acrylonitrile at 30 of 91 orthoselectivity and interactions among the furan tals opposite elements: charge tals with alkenes can be a result result opposite things: acrylonitrilefavor orthoselectivity, steric variables market metaselectivity [32]. [32]. (entry alkene orthoselectivity, although when steric factorsregioselectivity of reactions ofwere observed According 91 calculations, the market metaselectivity and favor at 30 ,to DFTfurfural acetals with and moderate endoselectivity furanic acetals and alkene10). IMDA cycloadditions oforthoselectivity alkenes. Table 3.Table three. IMDA cycloadditions of furfural acetals with alkenes. Table 3. cycloadditions of furfural acetals with alkenes. Table 3. IMDA IMDA cycloadditions of furfural acetals with alkenes.2.2. Furanic Acetals(entry 10). According of two opposite components: charge interactions between the furan acewith alkenes is a resultto DFT calculations, the regioselectivity of reactions of furanic and alkene favor orthoselectivity, whilst steric variables promote metaselectivity [32]. the furan tals with alkenes is usually a result of two opposite variables: charge interactions between and alkene favor orthoselectivity, although steric elements promote metaselectivity [32].Table three. IMDA cycloadditions of furfural acetals with alkenes.Int. J. Mol. Sci. 2021, 22,tone, methyl acrylate or acrolein at 60 , a mixture of regio- and stereoisomers was obtained with predominant meta- and endoselectivity. Inside the case of acrylonitrile reacting with furanic acetals, the selectivity of cycloadditions was poor even inside the presence of Lewis acid catalysts (entries five). For the ZnCl2-catalyzed reaction of ethylthioacetal with acrylonitrile at 30 , 91 orthoselectivity and moderate endoselectivity have been observed (entry ten). In accordance with DFT calculations, the regioselectivity of reactions of furanic acetals with alkenes can be a result of two opposite aspects: charge interactions among the furan and alkene favor orthoselectivity, when steric things market metaselectivity [32].eight ofTable 3. IMDA cycloadditions of furfural acetals with alkenes.Table three. IMDA cycloadditions of furfural acetals with alkenes.Furfural Yield of Adducts Dienophile Circumstances Selectivity Acetal, [ref.] Furfural Yield of Adducts Dienophile Conditions Selectivity Acetal, [ref.] N-MethylmaleiFurfural Yield of Adducts 1 CH2Cl2, 23 Endo/exo 87:13 N.d., [86] Dienophile Situations Selectivity mide Acetal, [ref.] N-MethylmaleiFurfural Yield of Adducts 1 CH2Cl2, 23 Endo/exo 87:13 N.d., [86] Dienophile Situations Selectivity mide Acetal, [ref.] N-MethylmaleiFurfural Yield of Adducts Methyl vinyl OrthoEndo/exo 87:13 13 (endo/exo 74:26), 1 CH2Cl2, 23 N.d., [86] Dienophile Conditions Selectivity two Neat, 60 36, [ref.] mide Acetal, [32] ketone meta 87 (endo/exo 65:35) N-MethylmaleiFurfural Yield of Adducts 1 CH2Cl2, 23 Methyl vinyl OrthoEndo/exo 87:13 13 (endo/exo 74:26), Dienophile Cond.