Synthetic cardenolides and related products. IV. <i>D</i>-homo derivatives

Ferland, Jean-Marie; Lefebvre, Y.

doi:10.1139/v84-054

Cited by 7 publications

(4 citation statements)

References 3 publications

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“…As ricciocarpin B ( 2 ) only differs from 1 within the five‐membered ring, we tried to convert 1 into 2 by oxidation (Scheme ). The bislactones 2 and 16 were obtained after [4+2] cycloaddition with singlet oxygen and subsequent thermal decomposition of the primary adduct as well as reduction with sodium borohydride 15, 16. By comparison of the analytical data with literature values1a 2 could be identified as ricciocarpin B 17.…”

Section: Methodsmentioning

confidence: 99%

Distribution of dendrites of descending neurons and its implications for the basic organization of the cockroach brain

Okada

Sakura

Mizunami

2003

J of Comparative Neurology

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To determine precisely the brain areas from which descending neurons (DNs) originate, we examined the distribution of somata and dendrites of DNs in the cockroach brain by retrogradely filling their axons from the cervical connective. At least 235 pairs of somata of DNs were stained, and most of these were grouped into 22 clusters. Their dendrites were distributed in most brain areas, including lateral and medial protocerebra, which are major termination areas of output neurons of the mushroom body, but not in the optic and antennal lobes, the mushroom body, the central complex, or the posteroventral part of the lateral horn. The last area is the termination area of major types of olfactory projection neurons from the antennal lobe, i.e., uni- and macroglomerular projection neurons, so these neurons have no direct connections with DNs. The distribution of axon terminals of ascending neurons overlaps with that of DN dendrites. We propose, based on these findings, that there are numerous parallel processing streams from cephalic sensory areas to thoracic locomotory centers, many of which are via premotor brain areas from which DNs originate. In addition, outputs from the mushroom body, central complex, and posteroventral part of the lateral horn converge on some of the premotor areas, presumably to modulate the activity of some sensorimotor pathways. We propose, based on our results and documented findings, that many parallel processing streams function in various forms of reflexive and relatively stereotyped behaviors, whereas indirect pathways govern some forms of experience-dependent modification of behavior.

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Section: Methodsmentioning

confidence: 99%

Distribution of dendrites of descending neurons and its implications for the basic organization of the cockroach brain

Okada

Sakura

Mizunami

2003

J of Comparative Neurology

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“…To our surprise, no conversion was observed upon treatment of 1 with m-chloroperbenzoic acid [21] or peracetic acid. [22] On the other hand, photooxygenation [23] of 1 was successful. After [4 2] cycloaddition with singlet oxygen and subsequent thermal decomposition of the primary adduct as well as reduction with sodium borohydride, a 1:1 mixture of the bislactones 2 and 17 was obtained.…”

Section: Full Papersmentioning

confidence: 99%

Enantioselective Synthesis of the Molluscicidal Furanosesquiterpene Lactones Ricciocarpin A and Ricciocarpin B via Ring Closing Metathesis

2002

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“…The bislactones 2 and 16 were obtained after [42] cycloaddition with singlet oxygen and subsequent thermal decomposition of the primary adduct as well as reduction with sodium borohydride. [15,16] By comparison of the analytical data with literature values [1a] 2 could be identified as ricciocarpin B. [17] To the best of our knowledge the transformation of 1 to 2 reported here constitutes the first synthesis of ricciocarpin B.…”

Section: Methodsmentioning

confidence: 79%