The Structure and Configuration of Resin Acids. Podocarpic Acid and Ferruginol

Abstract

The alkaline detosylation of 4-tosyl-D-man-nosan<l,5>/3<!,6> has been shown to proceed with Walden inversion and cis ethylene oxide ring formation to yield an anhydro derivative which is presumably 3,4-anhydro-D-talosan< 1,5>/3<1,6>. The anhydro compound, upon treatment with an acid acetylating mixture, yields a mixture of D-mannose and D-idose pentaacetates. The hexoses present have been identified by conversion of the acetates to characteristic hexitol hexaacetates. The reactions outlined are in agreement with other reactions in the carbohydrate series involving Walden inversions with ethylene oxide ring formation and rupture, as studied especially by Robertson and his colleagues, and the present results justify the conclusion that the structure and the configuration of the anhydro compound are those of 3,4-anhydro-D-talosan-<l,5>d<l,6>.d-and L-iditol hexaacetates form a crystalline racemate which melts much higher than the components and differs from them in crystallographic optical properties. Bethesda, Md.

Synthesis of Compounds as Melatonin Agonists and Antagonists

“…The methoxyl and amide substituents have to be the appropriate distance apart. The heterocyclic ring was synthesised after the 3-substituted side chain was partially in place, Fig [85,86]. The heterocyclic ring was synthesised after the 3-substituted side chain was partially in place, Fig [85,86].…”

Formal Total Syntheses of (+)‐ and (–)‐ar‐Macrocarpene via Rh(I)‐BINAP Catalyzed Conjugate Addition

“…Retrosynthetically, we imagined that enantioenriched 3‐arylcyclohexanone 12 may serve as an advanced intermediate for asymmetric synthesis (+)‐ ar ‐macrocarpene ( 1 ) via a Wolf‐Kishner reduction,, which in turn could be accessed from a catalytic enantioselective ( p ‐tolyl)boronic acid addition onto 5,5‐dimethyl cyclohexen‐2‐one 13 (Schemeà) …”

Practical and Efficient Strategy for Synthesis of Ferruginol, Sugiol, and Sugiol Methyl Ether from Geraniol

“…Thus, the unique and simple structure of aromatic abietane diterpenoids can be used as a template for lead compounds in the development of new drugs that are derived from natural products. Although several methods have been developed for the synthesis of 1 , 2 , and 3 from, e.g., podocarpic acid, dehydroabietic acid, clareol, dehydroabietylamine, 2,2,6‐trimethylcyclohexanone/sodium p ‐methoxyphenylacetylide, and α ‐cyclocitral, some have disadvantages including multiple steps, tedious separation, and expensive starting materials. Herein, we report a practical and efficient strategy for the synthesis of 1 , 2 , and 3 from a simple starting material: geraniol (Scheme ).…”