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A useful synthesis of (R)-[N-methyl-3 H]quinuclidinyl benzilate methiodide is described with the product characterized by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), tritium nuclear magnetic resonance (NMR), and mass spectrometry (MS). Several methods are provided to purify the radioligand, and its storage and stability are also discussed.

Computational analysis shows that the enantioselectivity of asymmetric Lewis-acid organocatalysis of the Diels–Alder cycloaddition of cyclopentadiene to cinnamates arises from stacking interactions that favor the addition of the diene to the more hindered face of the dienophile, while electrostatic interactions control the diastereoselectivity by selectively stabilizing the endo transition state. These results not only explain the stereoselectivity of these silylium-ion-ACDC reactions but should also guide the development of more effective ion-pairing asymmetric organocatalysts.

Concise biomimetic syntheses of the Strychnos-Strychnos-type bis-indole alkaloids (-)-leucoridine A (1) and C (2) were accomplished through the biomimetic dimerization of (-)-dihydrovalparicine (3). En route to 3, the known alkaloids (+)-geissoschizoline (8) and (-)-dehydrogeissoschizoline (10) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza-Michael/spirocyclization sequence over the alternate hetero-Diels-Alder cycloaddition reaction.

ConspectusNoncovalent interactions are ubiquitous in organic systems, and can play decisive roles in the outcome of asymmetric organocatalytic reactions. Their prevalence, combined with the often subtle line separating favorable dispersion interactions from unfavorable steric interactions, often complicates the identification of the particular noncovalent interactions responsible for stereoselectivity. Ultimately, the stereoselectivity of most organocatalytic reactions hinges on the balance of both favorable and unfavorable noncovalent interactions in the stereocontrolling transition state (TS).In this Account, we provide an overview of our attempts to understand the role of noncovalent interactions in organocatalyzed reactions and to develop new computational tools for organocatalyst design. Following a brief discussion of noncovalent interactions involving aromatic rings and the associated challenges capturing these effects computationally, we summarize two examples of chiral phosphoric acid catalyzed r...

Several studies have indicated that in birds breathing frequency (f, breaths min−1) scales to the −1/3 of body weight (W, kg); this is different from the −1/4 of mammals. We wondered if this discrepancy was due to the peculiar scaling pattern of aquatic birds, as is the case of aquatic mammals. In fact, we had noted previously that the allometric scaling of f differs considerably between aquatic and terrestrial mammals, respectively, W−0.42 and W−0.25. Measurements of f were obtained in 48 aquatic birds of 22 species and in 35 terrestrial birds of 27 species, during resting conditions on land. Additional data from 11 aquatic and 14 terrestrial species, different from the ones measured, were obtained from the literature. The allometric curve of all species combined (terrestrial and aquatic, n=74) was f=13.3W−0.36, similar to what is reported in previous studies. However, the allometric curve of the aquatic species (n=33, f=14.5W−0.56) differed greatly (P

Concise biomimetic syntheses of the Strychnos-Strychnos-type bis-indole alkaloids (-)-leucoridine A (1) and C (2) were accomplished through the biomimetic dimerization of (-)-dihydrovalparicine (3). En route to 3, the known alkaloids (+)-geissoschizoline (8) and (-)-dehydrogeissoschizoline (10) were also prepared. DFT calculations were employed to elucidate the mechanism, which favors a stepwise aza-Michael/spirocyclization sequence over the alternate hetero-Diels-Alder cycloaddition reaction.

This is the first of two special issues of Real Estate Economics dedicated to the study of Real Estate Investment Trusts or REITs. The goal of these special issues is modest. Rather than attempting to provide a comprehensive survey of current research on REITs,1 our objective is instead to provide readers with a sampling of the various general directions of inquiry either about REITs or employing REITs. The volume of research on REITs has exploded in recent years. The objective of this introduction is to provide three non-mutually exclusive catalysts for this explosion, and to provide brief summaries of the studies contained herein.

∗∗∗ We investigate relations among inside ownership, managerial expenses, risk sharing and equity valuations. Our engine of analysis—Real Estate Investment Trusts (REITs)—provides a unique and rich framework for analysis since we can calculate extremely accurate measures of asset replacement costs, and hence relative valuation (Tobin’s q). Further, the nature of the financial statements allows us to examine the impact of insider ownership on agency costs since we can accurately measure the costs of the entire management team. Our results show that firms with greater insider holdings tend to invest in assets with lower systematic risk and use less debt in their capital structure. At the same time, managerial expenses are lower as inside ownership increases. Finally, higher levels of insider ownership are associated with higher relative valuation as measured by both higher premiums to net asset value and higher multiples of cash flows. The results have implications for the design of optimal management contracts for both REITs and firms in general. One of the more contentious issues in the finance literature concerns the relation between ownership structure and firm valuation or financial performance. Since at least Jensen and Meckling (1976), it has been well understood that managers have incentives to make decisions that are in their, but not necessarily their shareholders’, best interests. These agency conflicts can be eliminated by simply requiring that managers retain the entire equity stake in the assets they manage. Unfortunately this solution leads to inefficient risk sharing. Wealth-constrained owner‐managers are likely to be assuming large amounts of idiosyncratic risk when their wealth is concentrated in the firm they manage. Risk-averse managers will have to be compensated for bearing the additional idiosyncratic risk as their ownership share increases. Clearly, fractional outside owners can more easily and efficiently diversify. One consequence to allocating a greater ownership share to managers may be that they choose to reduce the risk level of the firm in order to reduce their

[Naphthyl-3H] WIN 55212-2 was prepared at high specific activity by the catalytic tritiation of dibromo precursor 3. Product 4 was characterized by chromatography as well as tritium NMR and proven to be a useful radioligand. Copyright © 2002 John Wiley & Sons, Ltd.

[Vinylidene-3H] (−)-α-Kainic acid was prepared by means of a Wittig reaction with a protected ketone precursor and has proved useful as a tool to study neuroexcitatory amino acid receptors. Copyright © 2002 John Wiley & Sons, Ltd.

In this study, we examine the relationship between the liquidity of equity and its market value. We find that creating liquid equity claims on relatively illiquid property assets increases value by 12‐22%. However, the fixed costs associated with creating these claims offset these liquidity gains for pools of assets below $100 million. We also estimate that the liquidity of individual properties adds 16% to their value relative to a notional nontradable property asset. Managers can enhance the liquidity of equity and, therefore, the benefits of securitization by increasing size, focus, and institutional ownership. In his seminal article, Coase (1937) addresses the fundamental question of why the corporation exists and prospers as an organizational form. Given that there are significant costs to forming a public corporation, including the cost of a management team and reporting costs, what benefits to public trading outweigh these costs? Coase and many authors that followed concentrate on identifying advantages along the dimensions of reducing contracting, monitoring, and agency costs. However, another branch of the financial economics literature has examined an alternative benefit of the publicly traded corporation: namely, the enhancement of the liquidity of the claims on the assets. Under this paradigm, a firm is viewed as a collection of illiquid assets arising from capital budgeting decisions. Bundling these assets into a corporation and issuing comparatively liquid publicly traded claims to these assets can create value if liquidity is priced.

We trace the effects of corporate focus by examining the relationships among focus, cash flows and firm value. In contrast to past studies that examine the effects of diversifying across SIC-code-defined industries, we show that diversification, even within a single industry, reduces value. Our evidence, drawn from a panel of real estate investment trusts, indicates that this reduction is not due to poor managerial performance. Project-level cash flows are actually higher for less focused firms. However, these gains are offset by higher management, administrative and interest expenses. Thus, the corporate cash flows available to shareholders are not related to focus. Finally, we provide empirical evidence that links the effect of focus on value to informational asymmetries which cause the equity of diversified firms to be less liquid. We attribute some of the effect of focus on the cost of both debt and equity to informational asymmetries or transparency costs.

We use the term structure of futures prices to test whether investors anticipate mean reversion in spot asset prices. The empirical results indicate mean reversion in each market we examine. For agricultural commodities and crude oil the magnitude of the estimated mean reversion is large; for example, point estimates indicate that 44 percent of a typical spot oil price shock is expected to be reversed over the subsequent eight months. For metals, the degree of mean reversion is substantially less, but still statistically significant. We detect only weak evidence of mean reversion in financial asset prices. IN THIS STUDY, WE provide evidence of mean reversion in the prices of several real and financial assets. Rather than examining evidence of ex post reversion using time series of asset prices, we use price data from futures contracts with varying delivery horizons to test whether investors expect asset prices to revert. This approach offers two advantages. First, since futures prices are readily available for many markets, our procedure can be implemented for many assets, including those for which reliable spot price data is elusive. Second, there is little ambiguity as to the source of any mean reversion detected using our method. Subject only to the maintained assumption that the no-arbitrage cost-of-carry condition holds, our test detects mean reversion that is expected to occur in equilibrium, but has no power to detect mean reversion resulting from noise or inefficiencies. Our methodology focuses on relations between price levels and the slope of the futures term structure, defined as the change across delivery dates in the futures prices observed on a given trading date. An inverse relation between prices and the futures term slope constitutes evidence that investors expect mean reversion in spot prices. To illustrate, initially assume there are no

Following the crash of 1987, one contentious regulatory issue has been whether margin activity exacerbated the decline in equity values. We contrast the crash behavior of NASDAQ securities eligible for margin trading with the behavior of ineligible ones. Consistent with the hypothesis that margin-eligible securities were more frequently subjected to margin calls and forced sales, we find that abnormal volumes were uniformly larger for eligible securities. However, there is no evidence that this activity provoked additional price depreciation. Margin-eligible securities actually fell by one percent less than the ineligible securities over the period.

The authors examine whether greater futures-trading activity (volume and open interest) is associated with greater equity volatility. They partition each trading activity series into expected and unexpected components, and document that while equity volatility covaries positively with unexpected futures-trading volume, it is negatively related to forecastable futures-trading activity. Further, though futures-trading activity is systematically related to the futures contract life cycle, the authors find no evidence of a relation between the futures life cycle and spot equity volatility. These findings are consistent with theories predicting that active futures markets enhance the liquidity and depth of the equity markets. Copyright 1992 by American Finance Association.

We use predictions of aggregate stock return variances from daily data to estimate timevarying monthly variances for size-ranked portfolios. We propose and estimate a single factor model of heteroskedasticity for portfolio returns. This model implies time-varying betas. Implications of heteroskedasticity and time-varying betas for tests of the capital asset pricing model (CAPM) are then documented. Accounting for heteroskedasticity increases the evidence that risk-adjusted returns are related to firm size. We also estimate a constant correlation model. Portfolio volatilities predicted by this model are similar to those predicted by more complex multivariate generalized-autoregressiveconditional-heteroskedasticity (GARCH) procedures. MANY RESEARCHERS HAVE NOTED that the variance of aggregate stock returns changes over time. For example, French, Schwert, and Stambaugh (1987) use daily returns to the Standard & Poor's (S&P) composite portfolio to estimate monthly volatility from 1928 to 1984. They estimate that the standard deviation of aggregate monthly returns was about four times larger in the 1929-1933 period than in the 1953-1970 period. This paper (i) investigates the relation between aggregate volatility and the variance of monthly returns to disaggregated portfolios of stocks and (ii) examines the effect of portfolio heteroskedasticity on some common empirical tests in finance. We start with a model which implies that the conditional covariance is a quadratic function of the conditional market standard deviation

Beta-funaltrexamine is a unique irreversible antagonist for the mu-opiate receptor and would be useful as a tritiated radioligand. Starting from high specific activity [15, 16-³H] naltrexone, [15, 16-³H] beta-funaltrexamine was synthesized and characterized by means of a two-step reductive amination-acylation process.