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A total synthesis strategy was developed for the synthesis of luotonin A, B and their analogues using synergistic FeCl3/KI‐catalyzed oxidative cyclization. This protocol utilizes cheap and widely available N‐propargyl 2‐methyl‐quinazolinones and arylamines under mild conditions, and it has a wide substrate scope and high atom economy. Different natural products (luotonin A, B and derivatives) can be synthesized via a unique switchable approach. Further transformations from luotonin B to luotonin E and structural modification of natural products demonstrate the potential applications of this method. Moreover, camptothecin can also be modified with the reported protocol to afford the hydroxyl‐substituted product. [ABSTRACT FROM AUTHOR]

ABSTRACT Drawing upon the literature in computational modeling, multivariable reasoning, and causal attribution, this study aims at characterizing multivariable reasoning practices in computational modeling and revealing the nature of understanding about multivariable causality. We recruited two freshmen, two sophomores, two juniors, two seniors, four master's students, and four PhD students in atmospheric sciences as participants. Participants' reasoning practices and understanding of multivariable causality were examined using semistructured interviews and recordings of their computer activities. Analyses show that participants with high expertise tended to take a mechanism approach to predict and identify relationships, focused more on multivariable relationships, and purposefully selected and tested variables. The findings also indicate that understanding about multiple causality involved recognition and identification of the integration rules of multiple effects and the attributes of variables (e.g., interactive and reciprocal) and relationships (e.g., direction and feedback loop). Additionally, this study suggests an interaction between participants' reasoning practices and their understanding of multivariable causality; participants' understanding about the integration rules and the attributes could initiate reasoning practices, and by the enactment of practices, the rules and attributes were confirmed and examined. This study provides insight into the nature of multivariable reasoning and the design of computer-based modeling tools. © 2013Wiley Periodicals, Inc. Sci Ed 97:337-366, 2013 [ABSTRACT FROM AUTHOR]

In the title compound, C(21)H(19)N(3)O(4), the central benzene ring makes dihedral angles of 78.54 (6) and 75.30 (6)° with the pyridine and 3-methoxy-phenyl rings, respectively. An intra-molecular N-H⋯N interaction occurs, generating an S(?). The crystal packing shows inter-molecular N-H⋯O hydrogen-bonding inter-actions between the N-H groups and the O atoms of the 3-methoxy-phenyl ring and the carbonyl groups of the amide functions. Inter-molecular C-H⋯O inter-actions are also present.