159454-99-6Relevant academic research and scientific papers
A Novel and Stereoselective Spiroannelation: A Facile Access to Aphidocolane and Stemodane B/C/D-Ring Systems
Tanaka, Tetsuaki,Okuda, Osamu,Murakami, Kazuo,Yoshino, Hitoshi,Mikamiyama, Hidenori,et al.
, p. 4125 - 4128 (1994)
Spiroundecane derivatives 6A and 7S were obtained in moderate stereoselectivity by the intramolecular spiroannelation reaction of a bis-acetal 3 promoted by TMSOTf, and the selectivity was reversed by changing the solvent from acetonitrile to THF.
Lewis acid-mediated stereoselective spiroannelation: A facile access to aphidicolane and stemodane B/C/D ring systems
Tanaka,Okuda,Murakami,Yoshino,Mikamiyama,Kanda,Kim,Iwata
, p. 1017 - 1023 (2007/10/03)
A novel and stereoselective spiroannelation reaction was developed. Treatment of the suitably functionalized cyclohexene derivative (3) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) afforded the spiro[5.5]undecanes 4A and 5S exclusively. Changing the solvent from CH2Cl2 to CH3CN or THF increased the stereoselectivity, predominant formation of 4A in CH3CN and 5S in THF was observed. The spirocyclic compounds 4A and 5S were transformed into the tricyclo[6.3.1.01,6]dodecane derivatives (19A and 27S) corresponding to the B/C/D rings of aphidicolanes (1) and stemodanes (2).
