Aphanorphine, a novel tricyclic alkaloid from the blue-green algaAphanizomenon flos-aquae

Toxic Alexandrium minutum (Dinophyceae) from Vietnam with new gonyautoxin analogue

“…In our HPLC analysis, a fluorescent peak appeared consistently between the peaks of GTX4 and GTX1. As a matter of fact, some non-PST compounds also gave false fluorescence signals in the post-column reaction system (Gulavita et al, 1988;Onodera et al, 1996;Sato and Shimizu, 1998) and remained under non-oxidizing condition. In our analysis, however, the peak disappeared under the non-oxidizing condition.…”

Diastereoselective Allylation of Carbonyl Compounds and Imines: Application to the Synthesis of Natural Products

“…216 The first step of the synthesis involved an indium-mediated stereoselective α-aminoallylation of p-methoxyacetaldehyde with methallyl bromide and (R)-tert-butanesulfinamide in the presence of indium and titanium tetraethoxide. The homoallyl amine derivative was obtained in 92% yield and 93:7 dr.…”

Flexible Gold‐Catalyzed Regioselective Oxidative Difunctionalization of Unactivated Alkenes

“…Compounds of type 10 largely incorporate the carbon framework of aphanorphines, which are marine natural compounds that resemble benzomorphane analgesics such as pentazocine. [17] To gain a deeper insight into the mechanism of these transformations, deuterium-labeled alkenes (E)-and (Z)-1 bd 1 were prepared and subjected to the standard reaction conditions (Table 1), thus affording trans-2 b-d 1 and cis-2 b-d 1 , respectively, as single diastereoisomers (Scheme 2). [18] Based on these results, different mechanistic manifolds can be outlined as shown in Scheme 3.…”