Synlett, Inhaltsverzeichnis Synlett 2014; 25(5): 713-717DOI: 10.1055/s-0033-1340669 letter © Georg Thieme Verlag Stuttgart · New York Stereoselective Synthesis of Dioxolanes and Oxazolidines via a Desymmetrization Acetalization/Michael Cascade David M. Rubush Colorado State University, Department of Chemistry, Fort Collins, CO 80523, USA Fax: +1(970)4911801 eMail: rovis@lamar.colostate.edu , Tomislav Rovis* Colorado State University, Department of Chemistry, Fort Collins, CO 80523, USA Fax: +1(970)4911801 eMail: rovis@lamar.colostate.edu › Institutsangaben Artikel empfehlen Abstract Artikel einzeln kaufen Alle Artikel dieser Rubrik Abstract The desymmetrization of p-quinols using a Brønsted acid catalyzed acetalization/Michael cascade was achieved in high yields and diastereoselectivities for aldehydes and imines. Use of a chiral Brønsted acid allowed for the synthesis of 1,3-dioxolane and 1,3-oxazolidine products in modest enantioselectivity. Key words Key wordsacetals - desymmetrization - Michael addition - stereoselective synthesis - cascade catalysis Volltext Referenzen References and Notes 1a Perron F, Albizati KF. Chem. Rev. 1989; 89: 1617 1b Aho JE, Pihko PM, Rissa TK. Chem. Rev. 2005; 105: 4406 1c Mavragani CP, Moutsopoulos HM. Clinic Rev. Allerg. Immunol. 2007; 32: 287 1d Scott JD, Williams RM. Chem. Rev. 2002; 102: 1669 2a Seebach D, Sting AR, Hoffmann M. Angew. Chem. Int. Ed. 1996; 35: 2708 2b Fache F, Schulz E, Tommasino ML, Lemaire M. Chem. Rev. 2000; 100: 2159 2c Agami C, Couty F. Eur. J. Org. Chem. 2004; 677 3a Frauenrath H, Philipps T. Angew. Chem., Int. Ed. Engl. 1986; 25: 274 3b Frauenrath H, Reim S, Wiesner A. Tetrahedron: Asymmetry 1998; 9: 1103 3c Burke SD, Müller N, Beaudry CM. Org. Lett. 1999; 1: 1827 3d Fletcher SJ, Rayner CM. Tetrahedron Lett. 1999; 40: 7139 3e Weatherhead GS, Houser JH, Ford JG, Jamieson JY, Schrock RR, Hoveyda AH. Tetrahedron Lett. 2000; 41: 9553 3f Hoveyda AH, Schrock RR. Chem. Eur. J. 2001; 7: 945 For examples of organocatalytic asymmetric acetal synthesis, see: 4a Cheng X, Vellalath S, Goddard R, List B. J. Am. Chem. Soc. 2008; 130: 15787 4b Čorić I, Vellalath S, List B. J. Am. Chem. Soc. 2010; 132: 8536 4c Čorić I, Müller S, List B. J. Am. Chem. Soc. 2010; 132: 17370 4d Čorić I, List B. Nature (London) 2012; 483: 315 4e Sun Z, Winschel GA, Borovika A, Nagorny P. J. Am. Chem. Soc. 2012; 134: 8074 4f Kim JH, Čorić I, Vellalath S, List B. Angew. Chem. Int. Ed. 2013; 52: 4474 5 Nagano H, Katsuki T. Chem. Lett. 2002; 31: 782 For examples of organocatalytic asymmetric aminal formation, see: 6a Rowland GB, Zhang H, Rowland EB, Chennamadhavuni S, Wang Y, Antilla JC. J. Am. Chem. Soc. 2005; 127: 15696 6b Liang Y, Rowland EB, Rowland GB, Perman JA, Antilla JC. Chem. Commun. 2007; 4477 6c Li G.-L, Fronczek FR, Antilla JC. J. Am. Chem. Soc. 2008; 130: 12216 6d Cheng X, Vellalath S, Goddard R, List B. J. Am. Chem. Soc. 2008; 130: 15786 6e Rueping M, Antonchick AP, Sugiono E, Grenader K. Angew. Chem. Int. Ed. 2009; 48: 908 7a Jefford CW, Jaggi D, Kohmoto S, Boukouvalas J. Helv. Chim. Acta 1984; 67: 2254 7b Jefford CW, Rossier JC, Kohmoto S, Boukouvalas J. Synthesis 1985; 29 7c Jefford CW, Jaggi D, Boukouvalas J, Kohmoto S. J. Am. Chem. Soc. 1983; 105: 6497 7d Jefford CW, Kohmoto S, Boukouvalas J, Burger U. J. Am. Chem. Soc. 1983; 105: 6498 For examples of diastereoselective cyclic acetal syntheses by intramolecular oxy-Michael addition via hemiacetal formation, see: 8a Evans DA, Gauchet-Prunet JA. J. Org. Chem. 1993; 58: 2446 8b Watanabe H, Machida K, Itoh D, Nagatsuka H, Kitahara T. Chirality 2001; 13: 379 8c Redondo MC, Ribagorda M, Carreño MC. Org. Lett. 2010; 12: 568 8d Evans PA, Grisin A, Lawler MJ. J. Am. Chem. Soc. 2012; 134: 2856 9a Asano K, Matsubara S. Org. Lett. 2012; 14: 1620 9b Okamura T, Asano K, Matsubara S. Chem. Commun. 2012; 48: 5076 9c Fukata Y, Miyaji R, Okamura T, Asano K, Matsubara S. Synthesis 2013; 45: 1627 9d Fukata Y, Asano K, Matsubara S. Chem. Lett. 2013; 42: 355 10 Rubush DM, Morges MA, Rose BJ, Thamm DH, Rovis T. J. Am. Chem. Soc. 2012; 134: 13554 11a Carreño MC, González-López M, Urbano A. Angew. Chem. Int. Ed. 2006; 45: 2737 11b Barradas S, Carreño MC, González-López M, Latorre A, Urbano A. Org. Lett. 2007; 9: 5019 11c Barradas S, Urbano A, Carreño MC. Chem. Eur. J. 2009; 15: 9286 12 The stereochemistry of the 1,3-dioxolane was confirmed using nuclear Overhauser effect (NOE) experiments on the minor diastereomer. 13 A 1.5 dram vial was charged with a magnetic stir bar, 4-methyl-4-hydroxycyclohexa-2,5-dienone (1; 0.25 mmol, 1.0 equiv), diphenylphosphinic acid (18 mg, 0.025 mmol, 0.1 equiv), aldehyde/imine (0.31 mmol, 1.25 equiv), and 1,2-dichloroethane or CH2Cl2 (1.0 mL, 0.25 M). The vial was then sealed and stirred at r.t. until the starting material disappeared by TLC (6–48 h). In some cases the reaction was heated to 45 °C. The reaction was concentrated in vacuo. Flash column chromatography (10–20% hexanes–EtOAc) of the resulting clear or yellow residue gave the analytically pure product in high diastereoselectivity as a white solid or clear oil. Some products decompose slowly upon treatment with SiO2 (via acetal hydrolysis) so fast column chromatography is optimal. 14 Gómez-Bombarelli R, González-Pérez M, Pérez-Prior MT, Calle E, Casado J. J. Phys. Chem. A 2009; 113: 11423 Zusatzmaterial Zusatzmaterial Supporting Information
