Biochemical Studies on “Bakanae” Fungus. Part 55 Synthesis of Gibberellins

In order to clarify the structure of ring A of gibberellins, thirteen lactones of cyclohexan series, of which eight were new, were prepared to examine their infrared spectra. So far; the experiment is concerned, γ-lactones show the characteristic absorption band in the rang 1775~1782 cm^?1 in dioxane, while 5-ones in the range 1730/~1762 cm^?1. Since the absorptio band due to lactone carbonyl of gibberellins occurs at the range 1777~1786 cm^?1 in dioxane, the lactone ring of gibberellins seems to be γ.     

The Synthetic Study of 2.3-Dihydro-lH-pyrrolo [1,2-a] indole Ring System

The 2,3-Dihydro-lH-pyrrolo[l,2-a]indole ring system was synthesised by the condensation reaction of toluquinone and 2-cyanomethylenepyrrolidine.     

Syntheses and Configurational Analysis of Rotenoids,XIX The Total Synthesis of Natural Rotenone

d,l-Derrisic acid (IIa, R′: H) was synthesized from d,l-hydroxy dihydrotubanol (Ve) by Hoesch condensation with a nitrile (VI). The possible optical resolution of d,l-IIa was demonstrated by a conventional “reversed resolution” method.

This communication and previous works constitute the first total synthesis of natural rotenone (Ia).     

Structure and Synthesis of a Minor Component in the Oxidation Products of Crude Natural Variotin Oxidized with Manganese Dioxide,and Its Reduction with Lithium Aluminum Tri-t-butoxy Hydride

The structure of a minor component in the oxidation products of crude natural variotin oxidized with manganese dioxide is elucidated. The synthesis of the investigated compound, N-(6-oxo-2,4-trans, tralls-heptadienoyl) 2-pyrrolidonide, and the reduction of the substance are also described.     

A Stereoselective Synthesis of Antimycinone A3 and Its Stereoisomers

Antimycinone A₃, which is a neutral fragment of mild alkaline hydrolysate of antimycin A₃, and its stereoisomers were synthesized stereoselectively from methyl trans-2-n-butylpent-3-enoate or methyl cis-2-n-butylpent-3-enoate, and natural antimycinone A₃ was proved to possess Hα-Hβ and Hβ-Hγ trans configuration.     

Chemical Studies on Ambergris

So called ambreinolal (IV),* a component of ambergris, was first synthesized by CrO₃ oxidation of ambreinolol (III)* which was obtained from ambreinolide (II) by reduction with LiAlH₄. Ambreinolol (III) was converted to the C₁₇-saturated oxide (VII) in a good yield through the monotosylate (VIII) by treatment with p-toluenesulfonyl chloride in pyridine.

Ambrein (I), a major constituent of ambergris, was easily converted to ambrein-tetrahydropyranylether (II), of which thermal decomposition gave back ambrein (I). The tetrahydropyranylether (II) was oxidized to ambreinolal-tetrahydropyranylether (V) in two steps. Ambreinolal-tetrahydropyranylether (V) was synthesized from ambreinolol (VII) in four steps and converted to the C₁₇-unsaturated oxide (VI) on heating.     

Syntheses of dl-N-Demethylvariotinyl 2-Pyrrolidonide (dl-Demethylvariotin), 2-Piperidonide,and ε-Caprolactamide

The syntheses of three dl-demethylvariotins are described.     

Availability of Energy in Alcohols,Aldehydes and Ketones by Growing Chicks

Biological availability of 23 alcohols, 16 aldehydes and 2 ketones was compared by the mini-test with chicks. Chicks can utilize methanol and ethanol, but not the alcohols of carbon chain from 3 to 9. Lauryl and myristyl alcohols were well utilized but those of higher carbon chain than 14 were not, mainly due to low digestibility. Glycerol and D-sorbitol were well utilized but not 4 other poly alcohols tested. Aldehydes and ketones with free carbonyl group showed low availability or even toxicity, but their derivatives with masked group showed no detrimental effect. Acetaldehyde, acetal and aldehydes of carbon chain longer than 9 were partially utilized.     

Availability of Energy in Ester and Ether Derivatives of Glycols by Growing Chicks

Biological availability of 33 esters, 17 ethers and 2 acetals of ethanediol, 1,2-propanediol, 1,3-butanediol and 1,4-butanediol was compared by mini-test with chicks. Chicks can utilize esters of ethanediol, 1,2-propanediol and 1,3-butanediol with acetic acid and fatty acids of carbon chain length from 5 to 12 with more improved palatability than that of free acids, while availability of esters of these glycols with propionic and butyric acids was low. Esters of 1,4-butanediol and ether derivatives of these glycols was not available, except ethyl ether of di-ethanediol which was partially available. Acetacetal of ethanediol was partially available but n-butyracetal was not.     

A Novel Synthesis of 3-Substituted Furans: Synthesis of Perillen and Dendrolasin

A novel synthetic method of 3-substituted furans was developed and syntheses of perillen and dendrolasin are described.